Heart Rot: The bridge between ecology and horticulture

I’m a lifelong student of pruning. I LOVE learning, observing, and theorizing over tree physiology and applying newfound thoughts and theories with curiosity and gratitude every pruning season. Earlier this week, I saw yet another article talking negatively about heart rot, which motivated me to finally finish my essay on the subject. In this essay I’ll talk positively about heart rot, tree physiology, pruning and orchard ecology.

Heart rot art: Texas? Peen? Elephant?

“That’s heart rot. The tree’s health is in decline” replied one horticulturalist to the above photo. “Hey, that’s heart rot…you had better apply a fungicide spray” replied someone else. And my response? Have you ever pruned an old tree?!

When it comes to pruning, I almost exclusively work with old trees and I see this a lot. Yes, it’s heart rot. No, I do not believe this tree is in imminent danger or even in decline, which is surprisingly a stance that not many people take. And so we’ll start there.

What is heart rot?
Heart rot is what happens when the pith of a tree (the center) starts to decay. The instigators of this core decay are fungi that get into the heartwood through wounds, broken branches, pruning cuts, etc. In a healthy tree, they only stay in the heartwood, which is the part of the tree that is not considered alive. It is often thought of as the dumping grounds for the tree, where minerals and older tree rings go to rest.

As fungi gradually work their way through the heartwood, the tree becomes hollow over time. In the timber realm, these fungi are considered harmful pathogens because they reduce the value of a log. Hollow logs= less money. This way of thinking, that fungi are harmful pathogens and hollow is unsaleable, somehow worked its way into horticulture, only this time… Fungi= harmful, Hollow=structurally unsound/sick/dying. So very rarely have I seen someone in the horticultural realm step back on the subject of heart rot to see the forest for the trees, which is why I’m writing this essay.

What is heart rot doing to the tree?
Way back in 2007, when I was doing a lot of forest inventory in Louisiana, I had to core all sorts of trees in order to assess their health and age. Often, after removing the core, I’d get sprayed with stinky water, spurted with methane from the hole I created, or witness a mass evacuation of insects. Lots of life inhabited those trees and that’s because heart rot fungi slowly made way for life to be there. This concept of rot-makes-habitat was really hammered home when I helped a USDA sniper tranq some inbreeding black bears that had chosen to calve in the cavities of old cypress trees. Straight up Winnie-the-Pooh habitat, those cypress swamps. Only poor Winnie was shacking up with his cousin in this scenario and had to move.

Original illustration of Winnie the Pooh by A.A. Milne
This tree is a pollarded tree

Fast forward 11 years to 2018, when I flew to Basque France to attend a conference on pollarding. It was there, surrounded by European foresters, forest engineers and horticulturalists, that everyone had a special place in their soul for heart rot and hollow trees, something I had never encountered before. A prevailing opinion, which I now view as a bridge between forest ecology and horticulture, was that heart rot creates hollows/habitats for all sorts of fauna. In hosting this fauna, the trees become collectors of poo (feces, not the bear). This creates an incredible microbial metabolism in the tree which, when combined with decomposing heartwood full of trapped minerals, supplies a steady amount of organic fertilizer that is slowly released to the base of the tree. Since trees store growth rings in the heartwood on an annual basis, this natural process of decomposition and fertilizing is a renewable. Hollow trees provide their own compost. That’s true sustainability.

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But isn’t a hollow tree a weakened tree?
The comparison I always see is that heart rot or hollowing makes the tree structurally unsound. I’m here to tell you that this is mostly an emotional reaction. In all reality (and some physics), the tree isn’t weakened at all until the trunk’s radius is 70% hollow1.

Mattheck paper cited at end of this essay

And keep in mind, that’s an un-pruned forest tree with a full crown. If the tree is pruned to allow for airflow and to correct for weight imbalances, the hollow tree is much more structurally sound. An old pollarded willow tree, for example, boasts complete structural soundness until the trunk’s radius is 93% hollow2 thanks to a radically reduced crown . This tells me that mostly hollow orchard trees (on good root systems. Eff dwarfing trees), if pruned regularly, pose very little structural threat.

What causes a hollow tree to ultimately fail?
When trees are hollow and the wind has a strong influence over them (most likely due to crown size and density), the circular trunk becomes a bit oblong. This creates a vertical crack, which is the ultimate shearing stress for the tree. Again, pruning for crown reduction in old trees really helps to avoid the development of these shear cracks.

Mattheck et al.

More explained through tree physiology.
Here’s the deal. Trees contain both sapwood and heartwood (see tree cross section picture at beginning of essay). The sapwood is the outer, living, layer of the tree that is responsible for carrying water and nutrients up to the canopy. Think of it as a bunch of tubes, or vessels (xylem), constituting the lifeline of the tree. Since this is one of the most important parts of the tree, it’s a heavy consumer of photosynthetic energy and a lot of that energy is spent on defense against pathogens (like fungi and bacteria) entering into this important area of transport.

If the sapwood is injured, the tree has an incredible and diverse defense process. One defense in particular that is easy to conceptualize is when tissues (parenchyma) outside of the vessels (xylem) cauterize the wounded vessels and separate them from sound vessels. In Malus, wounded vessels get plugged with a starchy-watery gum that is aptly named “vessel plug.” Other trees have tyloses instead of gum, and when the vessel (xylem) is injured, the parenchyma tissue grows into the cut chamber to seal it off3 .

I’m telling you about vessel plugs only to hammer home the point that sapwood has a lot of defenses that work tirelessly to keep invaders, whether from an accident or from decomposing heartwood, away from their life-transport network. This is part of the reason why maintaining a youthful vigor in a tree is important, because younger wood contains a higher ratio of sapwood to heartwood, increasing the defense capabilities of a tree on a minimal energy budget.

The higher ratio of sapwood to heartwood is also why it is better to prune younger wood on fruit trees. When pruning, the wound is much more efficiently cauterized and uses less energy.

Bonsen and Bucher


I’ll also note that the ability to cauterize, or create fast boundaries to some sort of attack, is often genetic. Look no further than fireblight tolerance in a durable apple like the Dula Beauty (triploid) compared to the sickly Esopus Spitzenburg to get a better idea of the genetic range.

Pruning larger limbs.
When I consider pruning larger limbs, the rule of thumb for me, unless a giant intervention needs to happen or I’m topworking (grafting in place), is that I often don’t cut limbs larger than 4 inches in diameter. This is strictly something I do in considering the tree’s energy. If the ratio of sapwood to heartwood goes down with age, then it takes a lot more photosynthetic energy (that starch-water mixture) to plug up a larger wound on an apple than it would a smaller wound. Add that energy expense to the tree simultaneously trying to activate dormant buds to create new growth, and even I’m exhausted. Let me be clear, though. I’m not doing this to protect from heart rot, which costs the tree relatively little energy. I’m doing this to help the tree balance its defense and growth energy.

Hollow trees in the orchard: Mycorrhizae
If you believe that hollow trees create their own compost and self-fertilize, and if you believe that pruning trees is a way to make hollow trees more stable, then let’s briefly mention mycorrhizae.

Mycorrhizae is the fungal network that is known to connect trees to other trees and allow them to talk and share resources. They connect trees to other resources by having their hyphae (or the fungal threads of mycorrhizae) grow in and around the tree roots. The roots release sugary exudates, which feed the hyphae and give them energy to go mingle. What causes a tree to release sugary root exudates? Pruning is one way, because tree branches are connected to tree roots. Once you start pruning a tree, the fine root system connected to those branches will die back. It’s not a 1:1 prune: root dieback ratio, as the root system is larger than the crown, but there is for sure some dieback.

What’s more interesting to me, however, is the confluence of fine root dieback from pruning, plant-microbe interactions from a hollowed out trunk and fungal hyphae in the soil. It’s a bit like Captain Planet; when these three powers combine, nutrient uptake and overall ecosystem health are enhanced. And this is why I’m on team ‘hollow tree.’ It’s almost as if the tree is creating it’s own “edge,” or diverse environment in which it and everything around it thrives in a wild and chaotic balance.

Final Comments (for now):

Instead of viewing hollows as condos for pathogens, view them as beneficial habitats that improve your orchard ecology. They are important refuges for all sorts of critters, from insects to birds, microbes to fungi, and maybe even a black bear (just kidding). Given how important these hollows are, NEVER! and I repeat, NEVER! Fill those holes up with concrete or bricks or anything else. Not only does it royally piss me off to ruin a chainsaw chain to some branch that was filled with concrete, but it’s not helping the tree in any way. And would you want to come home one day only to find your house filled with concrete? No.

Let’s keep an open mind to heart rot, ok? It’s performing a pretty amazing ecosystem service with no inputs from me.

NO NO NO NO NO NO NO NO NO NO NO NO NO!

Citations:

1.) Mattheck, C., Bethge, K., & Tesari, I. (2006). Shear effects on failure of hollow trees. Trees, 20(3), 329–333.

2.) Wessolly L, Erb M (1998) Handbuch der Baumstatik und Baumkontrolle, Patzer Verlag

3.) Bonsen, K. J. M., & Bucher, H. P. (1991). WHAT ARBORISTS HAVE TO KNOW ABOUT VESSEL PLUGS. Arboricultural Journal, 15(1), 13–17.

Know anyone who might want to sell a farm somewhere in the Eastern half of VA. I’m looking. Click here.

How to Make Bradford/Callery Pear Less Invasive.

Bird predation given fruit width.png

In my last essay, In Defense of Bradford Pear, I showed the above chart from Australia that correlated fruit size with bird species. Similar charts or descriptions have been found in publications from New Zealand, Spain, Japan and in the US, as well. Based on the correlation of fruit consumption with fruit size, I’ve decided to elaborate on the last essay in order to practically address Callery/Bradford pear invasiveness in the US in the best way I can.

Cedar Waxwing eating Pyrus calleryana in winter. Photo from Pilot Online

Due to Callery’s fruit size attracting our native songbirds, like American robins, cedar waxwings and gray catbirds, we can’t stop them from eating the little pears and pooping in marginalized areas like fencelines and worn out pastures. To think we can kill enough Callery pear to make a difference is a lesson in futility because 1.) We live in the United States and you can’t go kill a neighbor’s tree in the name of INVASIVES if they don’t want you to and 2.) Each tree produces thousands of fruits. So, with that said, here are my top solutions to sustainably make Callery pear less invasive and more useful.

1.) Citizen Breeding. What makes Callery pear invasive is its ability to produce copious amounts of small fruits, which birds then eat and distribute all over the place. It seems logical, then, to want to try and breed larger fruits into our populations of Callery in order to stop the spread by birds. In order to reduce invasiveness by around 80%, all it takes is getting progeny from the Callery/Bradford trees to produce fruits that are around an inch (25mm) in diameter. How do we do that? Allow them to hybridize with larger fruiting pears so the seeds dispersed by birds will have a higher likelihood of growing larger fruits…thus halting the invasion cycle.

What is needed to hybridize these pears and get them larger? For starters, you’re going to need a collection of pears that bloom at the same time as Callery, which is quite early. Russian/Cold Climate and early Asian pears are likely your best bet for this, so I went through the GRIN database (taxpayer funded genetic repositories) and have made a starter-list (there are a bunch more):

PI 541904- Seuri Li
PI 45845- Yaguang Li
PI 437051- Jubilee (cold hardy)
PI 541925- Kor 2
PI 267863- Pingo Li
PI 134606- Tioma (cold hardy)
PI 278727- La Providence
PI 278731- Sivaganga Estate
PI 307497- Seu Ri
PI 292377- Ranniaia Mleevskaia (cold hardy)
PI 541760- Chieh li x Japanese Golden Russet
PI 278729- Samy’s Estate
PI 541761- Chieh Li x Japanese Golden Russet 2
PI 541905- Szumi
PI 127715- Krylov (cold hardy)
PI 541326- Angelica Di Saonara
PI 324028- B-52 (cold hardy)
PI 541290- Mag 1 (cold hardy)
PI 132103- Shu Li
PI 312509- Tse Li

Appreciate this list? Help fund this type of work and more by purchasing charcuterie from www.hogtree.com.

You can request free scions online from September 1 to February 1 of every year from GRIN. You can also probably buy many of these cultivars online. From there, I highly recommend you share scions of these for free every winter, as I plan to do, in order to help infuse larger fruiting genetics into Calleryana.

You might notice there are a bunch of Asian pears in that list and you might think: Eliza, those pears are super fireblight susceptible! And you are right, of course, but think of it this way: MANY trees that are listed as fireblight susceptible are actually quite tolerant to FB once they are established and reaching sexual maturity. With Callery being an amazingly fireblight tolerant rootstock, this should help to get your topworked trees past the first 2 years of heightened susceptibility so they can start to fruit. Once these Asian pears intermingle with Callery, there are two possible outcomes:

1.) The hybrid offspring are more fireblight tolerant than the grafted Asian pearent’s tolerance

2.) The hybrid offspring is less tolerant to fireblight than the grafted Asian parent’s tolerance and will probably succumb to the disease and die on its own.

Either are a win-win, really.

Next, you’re gonna need to go into your pear thicket and do some cutting and grafting. There are two scenarios I see often:

1.) Field full of Callery: If you have a thick field of calleryana, I would recommend getting a forestry mulcher in and cut/mulch rows into the existing Callery stand. Then, run the mulcher to cut out trees within the rows left standing so the remaining are at 15 foot spacings. Top the trees you’ve left behind above deer browse ( throw into the alley and run over those, too, with the mulcher) and graft on the early blooming large fruited cultivars.

2.) Fenceline/Border with Callery: This is the scenario We’ve been dealing with over the past few years along the farm fenceline. First thing I do is flag the trees I want to keep, which are at 15 foot spacings along the fence. Then we cut out and chip all the non-flagged callery trees using my neighbor’s chipper (I mulch my orchard with callery pear wood chips). While we are cutting out the non-flagged trees, I go ahead and also cut the tops out of the flagged trees. I pick a height that is above deer browse height and also has a lot of clear wood without branches, because that helps with grafting. In April (I’m in zone 7a), I make fresh cuts on the remaining pear trees and topwork all of them to fruiting cultivars. We’ve been doing this for 3 years and 2018’s topworked pears will be producing fruit this year.

Topworked fenceline callery pear to a local french heirloom cultivar. This was grafted in April of 2021
Topworked fenceline callery pear to a local french heirloom cultivar. This was grafted in April of 2021. This is a smaller tree. I’ve topworked 7″ trees as well with amazing take.

This is totally doable and the result? An orchard of pears! You’d have to cut the tree down anyway if you were going to spray it, so why not turn it into a producing pear tree of value? My neighbors even pitched in to help us cut and chip in the name of supporting my vision and also getting rid of the fruiting portion of the Callery trees.

In two years, your top-worked pears will be flowering and the bees will mingle between surrounding landscape Callery/Bradford pears that weren’t able to be cut down and the large-fruited cultivars you have grafted. With callery pears being pollinated with the list of pears above, your chances of getting larger fruit to come up from the fertilized seed will exponentially increase, limiting its invasiveness if the fruit is an inch or larger in diameter.

2.) Use them as rootstocks! Every Callery pear growing is automatically the best pear rootstock around. For all of you people out there who are inundated with deer pressure, graft to the Callery pears to any pear you’d like (or Winter Banana apple) above the deer browse line. Sure, you’ll get lots of leafy re-growth off the trunk for a few years (which the deer or other livestock eat as tender shoots), but its also really easy to remove new growth with your hands or slightly older growth with pruners, and new shoots don’t have thorns. You’ll start to get fruit in 2-3 years.

One of the main reasons why Callery didn’t catch on as a rootstock, aside from root propagation failures and hardiness, is that they don’t produce dessert fruit (fruit meant for out of hand eating). This is the same reason why we’ve lost SO MANY fruit cultivars in the last 100 years. If you weren’t a dessert cultivar chosen by the cooperative extension to be grown in the early 20th century, you were phased out. However, in today’s markets, I believe large fruited Callery pear hybrids really have a chance in fermentation, specifically cider blends and perry (cider made from pears). They are high in sugar (over 16% brix on average for the 200 or so hybridized trees I’ve evaluated), and run the gamut in acidity, tannins, aromatics and unusual characteristics. Since these trees are so disease and pest tolerant, which allows them to grow and produce copious amounts of fruit without the hand of humans or chemicals, they stand to produce the most sustainable fruits and alcohol in humid temperate climates. We need more people working with them in order to make this happen because they aren’t apples and they need their own methods.

If you’d like to see more essays in general (I literally have 75 in draft form and many more in my brain), my time will need to be supported. You can do this through the donate button above or buy my company’s charcuterie from HogTree

The last essay left me with a bunch of hate mail and loads of baseless claims. In future essays, I’ll be debunking many of these claims in order to try and bring about a full picture. With that said, please send your strong opinions to fruitandfodder@gmail.com

Of Note: throughout the South and Southern New England, I have been noticing spontaneous hybridization in the “wild” between P. calleryana with P. communis (French) and/or P. pyrifolia (Asian). These trees have much larger fruits, usually golfball sized or larger, and are often loaded with fruits dripping from the trees because Callery genetics are heavy lateral bearers (perhaps an indicator phenotype for these hybrids). No research that I can find has evaluated the genetics of these larger fruited callery-like pears to see what exactly they are crossed with, but I’m happy to help supply specimens if anyone out there takes an interest.

The Launch of HogTree

Last year I went through a collapse. The best I can describe it is the imagery of me walking down a dirt road while being shot with arrows. I tried to pull them out and fight back with the first few shots, but more shots  continued to hit and sink into my flesh. By late fall, the fight was gone in me. I was bleeding out and in a dark place. I had no choice but to let the darkness envelop me.

During this period of time, I questioned myself, my life, my passions. I felt hollow. What was it all for? If I am to pursue my passions, will I always suffer like this? And how much more can I handle before it’s no longer worth it?  As these questions floated by me in the darkness, I heard a voice whisper: “Eliza, you are here to love apples.

It wasn’t the first time and I have a feeling it won’t be the last time that apples pull me out of depression. Slowly and incrementally, I started to give myself time to think about the things I loved and the patterns of my life. With each passing day of thinking about what I loved, business plans emerged. Caution and negative feelings turned into strategy. Conducting a personal inventory on what I had in my possession turned into talks, workshops, and mulberry trees for sale. When put all together, HogTree emerged.

HogTree Logo

First of all, what is HogTree? 

HogTree is a diversified orchard system designed and synched to the rotation and feeding of livestock while also growing commercial process fruit. Imagine a paddock filled with trees that drop fruit/nuts at the same time. Now imagine many paddocks incrementally dropping fruit from May through November. That is HogTree.

I have mulberry cultivars that will drop fruit from May through July. I have around 30 apple cultivars that, when put in order, will drop fruit from late June through November. I have special genetics gathered from notable Quaker horticulturalists like J. Russell Smith, John Hershey and Yardley Taylor to add to this system as well, including: persimmons, chinquapins, chestnuts, pears, pecans, oaks and hickories. In essence, HogTree is a practical arboretum designed to preserve rare or otherwise unwanted cultivars in order to feed livestock…and more.

Screen Shot 2018-04-05 at 10.30.50 AM

Summer drop scheme for apples in my area.

Why would you design an orchard to feed livestock? Because that’s the first income layer. If you are going to start an orchard, you’ll need to make some income during the time it takes for the orchard to start bearing (This is also important when trying to get a loan from the bank).  Some people grow annual vegetables and I think that’s perfectly fine, however I do not want to spend all of my time bending over. I’m a much happier person if I reach up rather than down. I also want to incorporate an income stream which will help manage the orchard throughout its lifetime. After a few years of having pigs in orchards, I’ve discovered that pigs do the job of an unskilled intern and deposit fertility in the process.

What about the second layer? That’s commercial process fruit production. Interspersed within these paddocks in inventive ways are cultivars which grow well for me in this area and have a high quality in value-added markets. These fruits will be mostly managed by livestock with a few steps of intervention coming from humans. Though it’s 5-6 years out, I’ve already promised this fruit to amazing makers/friends/business people who will not only treasure this fruit and turn it into the best product they can, but who also give a shit about our impacts on this earth and humanity. My fruit will go towards producing products with a positive and aware message.

Ugly Apples

Before I go to the next layer, I also need to put out a disclaimer. When I first got into apples, I wanted to grow alllll the varieties. I wanted to find uses for them all, so people could feel as rich as I felt when having access to hundreds of varieties/tastes/textures/uses.  I started growing heirloom apples for cider because they otherwise had no market due to natural cosmetic blemishes/weirdness, but were too special and delicious to me to not be given a purpose. In growing them for livestock first, process second, I’m giving them a new niche.

Is there a third layer?  Yes, the nursery layer. This year I’m selling the Hicks Everbearing Mulberry along with what we think is Stubbs Everbearing Mulberry (positive ID coming next month (May)) through HogTree. Both were championed by J. Russell Smith and John Hershey for being the original “Hog Trees,” with each tree responsible for feeding pigs and chickens for 3+ months in the South.  I sold 250 newly grafted trees in January, which are shipping out now, but this coming winter I will be selling hundreds more as 4-5 foot tall trees. In the next few years, I’ll start to sell the apples, chestnuts, chinquapins and persimmons that are part of my drop scheme. HogTree is an orchard system.  In selling these trees, I’m selling the order in which they belong in the scheme.

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Fourth Layer? Of course!:  Talks. Workshops. Tours. Helping people to learn from my mistakes. U-Pick (If you have a system designed to efficiently rotate livestock through, humans are no different).

There are more layers, but this is the 5 year layout as of right now. Now to reality!

What do I have right now? I have an 8 month lease on 10 acres in Loudoun County, Northern Virginia. The 8 month lease is so I can prep the ground for orchards to go in this winter with pigs (an annual income), while also keeping  a healthy dose of caution related to land tenure. In 8 months, the landlord and I should be able to see if it’s a good fit and will then discuss a long-term lease.  I’ve been burned badly in regards to land tenure and much like being in a romantic relationship, I do not feel comfortable planting trees which will be around for my lifetime after the first couple dates between me and the landlord. Working with pigs as my first activity on this new property feels safe, whole and doable.

10 pigs will be arriving in early May from David Crafton, of 6 Oaks Farm. He is a passionate wealth of information and all of his pigs are from pasture genetics, so they contain the necessary gut biome to raise them in an orchard-in-the-making setting. He has been working for years to develop his own breed, the Carolina Forest Spot Hog, but in waiting for this breed I’m receiving a heritage-breed mix from him largely consisting of a large black x tamworth cross and bluebutt crosses. The goal is 200+ pounds of delicious marbled red meat in 7 months with them eating 90% pasture/fodder. I’m excited to work with them.

rsz_screen_shot_2018-04-22_at_42052_pm

With that said, this timeline is how I currently predict HogTree will be developed in the next few years:

Year 1: The land is responsibly “pigged,” removing grubs, spreading minerals/nutrients and planting cover crops after them in order to prep the ground for orchard plantings. This is also a trial run for a long-term lease with the landowner. These pigs will be supplemented with some off-farm feed (non gmo peas, barley and whey mostly) because they are working to transition a blank canvas/pasture into an orchard and will need some supplement to grow within my 7 month time frame. HogTree the nursery sells mulberry trees online.

Year 2: (If pig year 1 pans out, otherwise repeat yr 1 on new piece of property), I will be planting fodder trees and fruit tree rootstock. Considering fodder trees,  I have the genetics for trees whose leaves are as nutritious as alfalfa and way more drought tolerant, providing high digestibility/minerality and nutrition when the grass starts to underperform. These trees will be harvested annually starting in year 3. HogTree continues to sell mulberries online.

Year 3: The fruit tree rootstocks will be topworked (grafted). In addition to pasture, the pigs will be eating tree fodder and early season mulberry fruit by this point.  HogTree sells summer apples and mulberry trees online.

Year 4: Pigs will hopefully start to taste their first apples off some trees. They will continue to eat pasture and leaf fodder from the trees. The full gamut of fruit trees will be available through HogTree.

Year 5+: Pigs will be fed/fattened/finished off tree leaves, fruit, nuts and pasture. Harvests for process fruits will begin.

*In order to make this vision and business plan work, I will need the investment of consumers. That means I am opening up a waiting list for 20lb box/quarter/half/whole hogs for the 2018 year. Please realize that in buying this pork, you are supporting the future of HogTree’s orchard system, which will show the important links between animals and orchards. Please consider buying pork from me if you want to see HogTree set this orchard system into motion. Click here to get on the waiting list!*

Update: Support my writings and more through the purchase of charcuterie at www.hogtree.com

HogTree Logo

Wanted: June Ripening Apples (and Pears)

IF YOU HAVE INFO ON ACTUAL TREES RIPENING APPLES/PEARS IN JUNE IN ZONE 7 OR COLDER, COMMENT ON THIS BLOG!!! 

Summer apples are rarely of interest to most apple growers and consumers. Compared to their later season kin, they bruise easily, are often described as lacking texture (or “mealy”), low in sugar, and having a very high acidity. They might not seem very fun from this brief description, and I’ll go into detail of why these apples are fun for me in a bit, but first: Light hearted stereotypes of people who find/have found summer apples to be exciting:

1.) Elderly people from New England & other places labeled “Cold as Hell”

videoblocks-elderly-couple-holding-apple-basket-happy-woman-and-man-outdoors-how-to-grow-fruits_sdoyygptl_thumbnail-full01

Picture taken from a google search

In my own personal experience, 90% of people over the age of 80 know of the Russian cultivars “Red Astrachan” and/or “Yellow Transparent” because of apple sauce. These are the first popular apple cultivars to ripen in New England and have a relatively thin skin that disintegrates when cooked down into sauce. That disintegrating skin quality, by the way, is a big factor defining a “sauce apple.” If you have to peel it before you cook it/have to use a food mill to get the peels out: It’s not a true sauce apple.

I made some apple sauce this year from an old Yellow Transparent tree in Northern VA (Apples cored, halved + Pot + Stovetop) and my tasting audience (employees of Southern States Cooperative), thought it was too acidic. I, the person who subsists on apples for months out of the year, thought it was great. But I’ve realized that my area in Virginia has lost much of its culture surrounding summer apple sauce. In New England, it seems to still be alive…for now.

2.) People alive in the early-mid 1800s

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A woman from NY reaching for a Yellow May apple from VA, as her trees are still in bloom.

In researching early ripening apples in my home state of Virginia, I’ve run across several accounts of growers from Southern Virginia selling “Yellow May” (a June Ripening apple for them) to New York markets for a pretty penny. Turns out, before the Russian cultivars (like red astrachan and yellow transparent) hit the scene, people in the Northern states were hankering for apples in June and buying them from the South. They probably ate them, rather than making sauce, because I don’t think texture was as big of an issue as it is now (thanks, apple lobbyists).

Why am I looking for June ripening apples?

Quick answer: For animal fodder

Long answer: It is my ambition to create animal paddocks based on drop times of fruit. WHAT THIS MEANS: I will one day be able to rotate animals from paddock to paddock and have that synched with drop times. Their feed will entirely be the grass growing in the orchard and the dropped/shaken-off fruits from the next level up. I’ve done quite a bit of work/collection for the later months, but the early months are much harder.

WHAT AM I LOOKING FOR?

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Anyone north of Virginia, in mountainous areas, or familiar with the USDA plant hardiness zone map 7a/7b*: If you know of an apple that produces in June and can get access to it/provide contact info to me, I would love to hear about it. The perfect scenario is this:

1.) I’m provided with some background info on the tree you’ve identified as a June bearing apple. This includes location, what you think it might be called, when in June it bears (early June/late June) and any other info you can find (bloomtime is something that comes to mind, but not that important). This is so I can keep notes on your selections and credit you in the future! Pictures are also a huge help.

2.) You can either take scionwood from the tree or get me the contact info so I can write/call the owners and see about getting some scionwood from this tree. I will gladly pay for your time and effort. Please, before taking scionwood, reach out to me so I can make sure we are on the same page as to what scionwood actually is.

3.) You mail the scionwood to me and I compensate you and credit you in future descriptions and work!

Other items of note:

I DO NOT CARE HOW THIS APPLE TASTES/TEXTURE/SMELLS/LOOKS. AT ALL.

I DO NOT CARE WHETHER OR NOT IT GETS BAD DISEASE (but would love to hear about this if you have info)

I DO NOT CARE IF IT HAS A NAME OR NOT

I DO NOT CARE IF IT IS GRAFTED

I DO NOT CARE IF YOU ACTUALLY HAVE A JUNE BEARING PEAR. That’s amazing, too, and I want to hear about it.

I ONLY CARE IF IT BEARS IN JUNE. Come one, come all…get in touch with me if you know of a June apple bearing in slightly colder climates.

*The reason why I ask for zone 7a/7b or colder (the lower the zone number, the colder) is so I can extrapolate. If someone in zone 5 has a first week of June apple, that could very well be a mid-late May apple for me. May apples in Northern VA are non-existant as far as I know, and I’m also very interested. The earlier the bearing, the more diverse of a diet my animals get earlier in the season. 

 

 

 

 

Dwarfing Mulberries: An Afternoon with Dr. A.J. Bullard

“Over here are the mulberries. This one is a pure Morus rubra that produces 2 inch fruits.” “Liza. Can you tell me what is different about this tree?”

This is the way of Dr. A.J. Bullard. He playfully taunts you with little snippets from his 70+ years of tree knowledge and then immediately follows it up by asking you seemingly impossible questions. “What is different about this tree?” 

Dr. A.J. Bullard isn’t a former horticultural professor, but a former baseball player and Dentist who is a botanical wiz. He reads botanical textbooks and then writes letters consisting of page upon page of single spaced revisions and fact checking to the authors. The most common complaint he voiced to me in reading these texts was how everyone seems to copy information from book to book rather than doing the research for themselves. Dr. Bullard is that man, the guy who has studied the intricacies of the Southeastern plant world so thoroughly and in real life that he often receives identification questions which have stumped the arboretums and universities (and he figures them out).

I didn’t know this about A.J when I went to visit him. I knew of him as the former president of the North American Fruit Explorers (NAFEX) who probably knows more about mulberries than anyone in the US. His knowledge is integral to the advancement of mulberries as a tree crop in the United States.

This blog post/essay is in relation to a running conversation about mulberries that I’ve had with A.J ever since we met (my boyfriend would tell you that I talk to A.J on the phone more than I talked to him when we first started dating).  The full conversation will be in the form of a presentation at this year’s annual NAFEX/NNGA conference in Tifton, Georgia. Among the multitudes of reasons why you should be there, hearing A.J. talk is one very, very good reason.


“What is different about this tree?” 

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Slowly, we approached the above pictured mulberry tree and he asks us again: “What is different about this mulberry tree?” I think on it for a bit and come up with nothing, so he asks again. “What do you see that is different with this tree?” I got nothing, A.J. No idea. “What about the height? It’s no taller than 12 feet,” he says. Ah, right…mulberries aren’t normally 12 feet tall unless they are a naturally dwarfing cultivar. “Correct!” “What if I told you this wasn’t a dwarf cultivar? What if I told you that I have figured out how to dwarf mulberries?”

Dear readers- Have you ever had your mind blown? It’s a flooding of immense realization and wonder and excitement, all at the same time. What I’m about to tell you not only blew my mind, but in a strange way paralleled my own exploits.

Dwarfing trees is a huge deal these days. Thousands and thousands of orchard acres are getting converted yearly into dwarfing orchards because 1.) more trees per acre=more fruit per acre 2.) smaller trees are easier and cheaper to manage/harvest. If you pick up an fruit industry magazine, there’s usually a very good chance of the magazine featuring one article on the promise of better dwarfing rootstock for pears/cherries/peaches/name fruit tree in the coming years because that’s where the industry is headed. However, there are some downsides to all of this and it’s usually in these three sectors: Costs (because trellis systems or support posts are expensive, Longevity (dwarfing rootstocks are shorter lived, maybe 25 years), and Input (these trees require tending from humans or else they’ll suffer and/or die).

What A.J has done to get dwarfing mulberries would allow an orchardist to fit close to 200 mulberry trees per acre. It costs less than, say, planting the same number of apple trees per acre on an m26 rootstock (semi-dwarfing) because the trees you plant are able to stand up without the need for support posts. They are longer lived (the trees pictured are 40 years old). And there are no chemical or water inputs necessary (other than establishment necessities).

Mulberry trees are naturally tall for fruit trees, usually around 30 feet or more (for M.alba and M.alba x M.rubra hybrids). Given the standard size, if you were to prune heavily every year, you could probably fit 70 trees per acre (more like 40 trees per acre if you didn’t prune heavily). With Dr. Bullard’s dwarfing methods, you could likely plant 3-5 times that amount per acre. Which, just to throw it out there, would be an incredible set up not only for people wanting to sell mulberries, but also for pastured chicken or pastured pork operations (more about that later).

Alright, so what goes into Bullard’s dwarfing methods? Note: What I’m about to discuss is only an hypothesis. We don’t know what is actually going on, but this is our best guess. Well, we think the name of the game is incompatibility. If you study the history of apple rootstocks like I have, it’s only a matter of time until you start to come across accounts of rootstocks (aka, the roots to which you graft your cultivar/scion/variety) imparting various characteristics into the cultivar/variety (here’s a fun essay on the subject I wrote last December). Some characteristics include a change in flavor, tree size, fruit size, disease resistance, yields, and death, among other things. Some of these characteristics (like death) are deemed incompatibilities. Keep this in mind.

Alright, so what did A.J do?

He took Morus alba (white mulberry- brought over from Russia in the 1600’s for silk production) and to it, he grafted Morus rubra (red mulberry-our native mulberry) or a rubra x alba hybrid. He planted the grafted trees in pots and let the rubra send out a vigorous shoot. Then he tightly wrapped a copper wire just above the graft union and buried the whole tree, leaving a small amount above ground. What grew up from there became a dwarf mulberry tree. Across the boards. At one point in time, he had an orchard of around 150 cultivars and he employed this method to fit them all into his yard. If you look at the above picture, you’ll see other dwarfed mulberry trees- all different cultivars.

He put the trees on their own roots using a method very similar to the one I made up 2 years ago (which you can read about in this essay). That’s part of the reason why my mind was blown, because I’ve been down this rabbit hole before with apples; only with A.J I got a chance to see a glimpse of what the future could possibly look like for my experiments. And also, there are major agricultural implications for this (a later essay).

Why does it work? We’re not totally sure, but we both think it could be some form of incompatibility transferred from the M. alba into the M.rubra which imbedded itself into the scion/variety/cultivar by the time the rootstock/nurse root girdled off and the tree was on it’s own roots. That incompatibility caused dwarfing. If you look at the ground where tree hits soil, you’ll see a bulge. Perhaps that’s where the vigor went.

Anyways- this is all very exciting and details of all of this, including how exactly to do it (which I’m doing as we speak) will happen this year at the NAFEX annual meeting in Tifton, Georgia.

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Old Orchard Restoration/Pruning 101 Workshop (note: it has been rescheduled for Jan 7th and 8th)

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January 7th & 8th, 2017: Apple Pruning 101 and Abandoned/Old Tree Restoration

*Notice! I have had to change the dates of this workshop due to agreeing to speak at the Horticultural Industries Show Conference in Arkansas. Sorry for the inconvenience!*

Location: Lovettsville, VA and Surrounding Areas
Click HERE to sign up!

This is a 2-day hands-on pruning intensive course which will cover everything you need to tackle an apple tree, young or old…kept or abandoned. Day 1 will cover the basics of pruning, from tree physiology to how to make a pruning cut to the considerations that go into making a cut. We’ll cover all sizes of apple trees from just planted to deer browsed to juvenile to mature trees. The day will end with participants breaking into supervised groups and working on trees. Day 2 will put into action all that we learned the day before, only this time we mean business. We’ll cover how to prune the big, burly, and the old. We’ll also cover top-working (changing a tree over to another variety) and the steps needing to be taken in order to graft a tree over to a new variety in spring. This class will be capped at 20 participants. Cost Per Person: 2 day workshop is $110, 1 day is $70.  Overnight lodging can be made available, ask for more details. In addition to money, work trade and barter are both acceptable means of payment.  CLICK HERE TO SIGN UP! 

watercore: a natural additive for hard cider in the south

I remember my first encounter with the “serious physiological disorder” called watercore. I was at an heirloom apple event in New Zealand, staring at a table full of old British varieties trying to decide which one to buy and eat first. I settled on a little russeted apple called Pitmaston Pineapple and once in hand, I took a large bite out of it.  The inside, to my surprise, looked like this:
watercored_cox
Photo Credit to Adams Apples
The taste was very sweet. A different kind of sweet, though, and it took me a year to come back around to figuring it out. This variety of apple, along with many other varieties, is susceptible to a “disorder” called watercore.
To the dessert grower, this “disorder” is bad news. Most people don’t want to bite into an apple which appears to have a water-soaked flesh because we’ve been taught that anything other than the usual white-crisp-juicy is to be avoided. However! I’m here to tell a different story, potentially one for the watery underdogs. A hopeful cider apple story.
First, let me give you some background on watercore…
To the apple industry, watercore is considered a “nonparasitic disease,” where the apple appears to have a water-soaked flesh. This “disease” takes shape in all apple growing regions of the US and seemingly has a few variants:
  1. Caused by a lack of water or droughty conditions
  2. Caused by a combination of genetics, the fruit being mature or overly mature, and sunscald due to intense heat.  
  3. Low calcium in your soils (which could go back to genetics since there are some calcium hungry cultivars, like Albemarle Pippin, which is known for watercore)
Why is it considered a disease? The brunt of it comes down to long-term storage. Apple packing houses aren’t able to store the apples with severe watercore because the tissues will eventually start to break down, causing the flesh to turn brown (and thus marked as unsaleable).  Another reason why it’s a bit of a bother to the apple industry is detection. Aside from some relatively recent research on detection methods, watercore has remained undetectable by the apple industry without the use of a knife (or teeth) to cut into the apple.
Like with the other apple diseases affecting the US, those with watercore are deemed as waste and dumped.  In my affinity for looking at common diseases as heroes of value-added products rather than boons to the established industry, I’m excited about watercore. Here’s why:
430-120176image20water20core20120correct
The area above that looks water-soaked is actually where the apple has flooded its air spaces with a solution of sorbitol,  a non-fermentable sugar alcohol which is not technically a sugar. According to Claude Jolicoeur’s Book, The New Cider Maker’s Handbook, sorbitol has a sweetening effect that amounts to about half the effect of white sugar. This means that when a cider or perry (cider made from pears) is fermented dry (the yeast eat almost all of the available sugar and convert it to alcohol), the presence of sorbitol would still have a sweetening effect on the dry cider (because it doesn’t ferment).
The idea of a completely dry cider with a nice, fruity, slightly sweet finish is very appetizing to me and happens to fall in line with my low-input management thoughts from fruit to bottle. Here’s my thought process (and some background story) on this one:
A long time ago, I was helping out in a cider house and they were sending a finished cider through a sterile (sulfited) filter to both strain the yeast from the bottle, but also to prevent any yeast that managed to slip through from reproducing.  I was asked to taste the water being sent through the filter to detect the sulfur taste and the very moment when that sulfur water hit my lips, I was struck with an immediate and very scary asthma attack. That day I learned that I’m in the 1% of Americans who are actually allergic to sulfites and ever since, I’ve been a canary in a coal mine with respects to unbound sulfites in alcohol and suffice it to say, I’m not a fan of the additive. It has ruined many a cider/beer/wine for me due to my lungs closing up.
But why the use of a filter soaked in sulfites in the first place? When a cider is fermented dry, there is little fear of the cider/bottle of cider becoming unstable because all of the sugar in the cider has been consumed and turned into alcohol.  If cider is bottled and has both alive yeast and sugar, the cider will continue to change in taste as the yeast convert the sugar to alcohol and more carbon dioxide is being created, which has been known to cause exploding bottles. In this situation, the sterile filter was being used because the cider was going to be backsweetened (the addition of sugar after fermentation) with apple concentrate to give the final product some sweetness (Americans love sweet). To recap: Backsweetening + yeast= off flavors and potential explosions. Backsweetening + filter + sulfites= a sweetened cider with less fear of re-fermentation.
What does this have to do with sorbitol and watercore? A higher presence of sorbitol in a cider means my cider can be fermented completely dry (free of sugar) while maintaining a minimal sweetness without fear of re-fermentation. Eliminating this fear of re-fermentation means that I can eliminate sulfites from the back end of my cidermaking process.
Watercore= Higher Sorbitol Content= Residual Sweetness in a Dry Cider With Less Chemical Inputs. ding. Ding. DING!
Ok, so let’s say that I’m sold on experimenting with this sorbitol/cider thing and I want to grow fruit in order to make this product. Being in the South, I have a lot of hope for achieving such a thing because the causal agents are: Intense heat, lots of sun (sunburn), low calcium, droughty conditions, and genetics.
In designing an orchard and keeping sorbitol production in mind, I would entertain the idea of going towards more of a dwarf set-up, perhaps even a trelli$ set-up on a southwestern facing slope. We’re talking steaming hot, dry, with the trelli$ed fruit being exposed to intense sun.  On top of that, the apple system would be on irrigation which would allow you to regulate the amount of water and when to apply it. I’d also layout the orchard in a way which would drain quickly (maybe even a keyline design ;-)). Next, I’d choose varieties which are prone to watercore and also those that tend to hang on the trees rather than drop (which is a good genetic trait for apples in the South, anyways). Apples heading towards being overripe are at risk of watercore, so those that hold on are perfect candidates.
If you wanted to experiment with trying to intensify sunlight into a non-trellised tree, I would still try and have super quick water drainage off your site and have a SW aspect, but you could also try some extreme things like spraying all the leaves off your tree in late summer. I’ve done this for reasons of reducing vigor by using a 501 biodynamic prep, which I sprayed in late summer and managed to burn a BUNCH of the leaves off the tree…on purpose. I think the trick with this is in having a very vigorous tree and also determining the point of no return for apple ripening (if such a thing exists). The spray I applied in mid-August slowed the ripening scheme, which doesn’t help my sorbitol thoughts. However! It makes sense to me that reducing the leaf load on the tree would certainly help the sun scald situation.
I’ve never heard of anyone trying to grow apples with watercore on purpose, but why not? In straying from dessert fruit growing, managing for a certain product like cider could give regions like the South a distinctive taste in their products. We often think about this in terms of varieties and landraces,  which are certainly a part of it. But let’s try and capture our environment and create a truly unique product which describes our place in every way.
*This essay has been in the works for far too long and I decided to push it through today. I’ll likely go back over it an link to things stored on my computer and correct spelling/grammar.*

 

 

Beneath An Ugly Outside, Marred Fruit May Pack More Nutrition

 NPR wrote an article about #eatuglyapples AND IT ALL STARTED WITH THIS BLOG! 

Unsightly scars on the outside of fruit might reflect higher nutrition within.

Unsightly scars on the outside of fruit might reflect higher nutrition within.

Daniela White Images/Getty Images

When orchardist Eliza Greenman walks through a field of apple trees and gazes upon a pocked array of blemished and buckled fruits — scarred from fighting fungus, heat and pests — she feels a little thrill of joy. “I’m absolutely infatuated with the idea of stress in an orchard,” says Greenman, who custom grafts and grows pesticide-free hard cider apples in Hamilton, Va. These forlorn, scabbed apples, says Greenman, may actually be sweeter.

 

Read more, HERE.

Hugh Ermen: Own-Roots Experimenter

Growing Apple Trees on their Own Roots

By Hugh F. Ermen (article appears on OrangePippin)

Hugh Ermen was one of the UK’s most successful modern apple breeders. He has raised Scrumptious, Red Devil, Winter Gem, Limelight, Herefordshire Russet and many others. He a leading exponent of the technique of growing apple trees on their own roots – rather than the standard practice of using dwarfing rootstocks. This is a copy of his work based on the experience gained over 25 years propagating and fruiting own root fruit trees of many varieties. Many fruit growers with long experience will know that growing a tree as naturally as possible is the best way.

Own root trees behave exactly as you would expect. Differences occur in trees on rootstocks due to the various degrees of incompatibility between stock and scion, which means there will be greater differences with dwarfing rootstocks.

Cropping will vary according to variety whether on own roots or rootstocks. I have found cropping more regular on own root trees, again as one would expect. Fruit size and quality at least as good but normally better. It has sometimes been suggested that we need trials to establish whether own root trees are better than trees on rootstocks. Having given this much thought, I would suggest this would be a waste of time and money. A trial would be influenced by the person conducting the trial whether intentionally or not. Of course apple trees grow well on their own roots, are the natural forests of apples on rootstocks?

The vigour of own root trees must be considered if you have little space. Triploid varieties will need more space than diploid varieties but I have found if they get the space they perform very well.

There are many basic techniques from planting to pruning which can be used to help control vigour, with cropping being the best control. For the newcomer to own root trees, I suggest starting with spur types and heavy cropping diploids. For the experienced person with enough space, the triploid varieties will not present a problem and you can always graft a fertile pollinator in the tree for the leader!

For the fruit tree nurseryman, the own root fruit tree should make propagation cheaper and reduce the risk of virus disease spread.

FRUIT ENTHUSIASTS – TRY OWN ROOT TREES!

Every variety of apple started life as a seed and in the past seedlings were selected growing on their own roots. Today the practice of apple breeders is to work the seedlings on to a dwarfing rootstock to bring them into cropping quickly. It is now well known, but often ignored, that degrees of incompatibility can exist between varieties and rootstocks, especially with the dwarfing rootstocks. It is probable that some potentially good varieties have been discarded in the past because partial incompatibility caused the seedling to give a poor performance on dwarfing rootstocks. A better but not necessarily quicker alternative would be to keep seedlings for assessment growing on their own root system. There are many well known ways which could be used to bring such seedlings into crop quicker.

As a general rule, the first seedlings to fruit from a batch of seeds are often flowering crabs, around year three to four. The next to flower are more likely to be good cropping diploid varieties. Seedlings that take six years or more to flower and fruit are usually moderate cropping diploid varieties. Triploid varieties are usually the last to flower and fruit which can take ten years.

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Comparison of Cox’s Orange Pippin trees growing on M( dwarf rootstocks (left) and own-roots (right). The own-root trees have the same vigor as Cox on MM106 semi-dwarfing rootstock.

Experience gained over the last thirty years has shown that assessing seedlings grown on their own roots gives more information to the apple breeder. It is very useful to know the natural vigour of a seedling, its’ growth pattern, cropping habit, fruit quality and natural resistance to pests and diseases without any rootstock influence.

 

The realisation that a rootstock influence on a variety is greater than at first thought, gives grounds to have a collection of the main apple varieties propagated on their own roots. This would reveal the natural characteristics of each variety and although more land would be needed than a collection on dwarfing rootstocks, this would be offset by double the lifespan of the own trees roots.

Growing apples on their own roots is not new. A reference can be found in the Transactions of the Horticultural Society of London where Mr Arthur R Biggs F.H.S., read a paper in February 1807. Only a few apple varieties could be propagated by cuttings, until research showed the way with use of heated propagating bins and micro propagation. Further progress with own root apple trees has been very slow, due to the major cut backs in Research and Development.

However, there is now enough experience with own root apples to make further development work worthwhile and the breeding of compact varieties to exploit the benefits and overcome the drawbacks.

Advantages of Own Root Trees

  1. Better tree health- Each variety differs in its precise nutritional requirements which can easily be achieved naturally, by growing a variety on its own roots. There is a difference between the uptake of nutrients by a rootstock and the exact requirements of the scion variety worked on it. This mismatch can lead to a reduction in the health of the scion variety and fruit quality.

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Red Devil on own roots, cropping heavily

  1. Better fruit set.
  2. When a variety that comes into growth early is worked on a late starting rootstock and flowers before the rootstock becomes active, poor fruit set will result.
  3. Better fruit quality and storage life
  4. Better resistance to pests and diseases
  5. Excellent for pot culture

Disadvantages of Own Root Trees

  1. No rootstock vigour control
  2. Insufficient development work at present on large scale propagation of own root trees.

A Vigour Guide To Own Root Trees

  1. Dwarfing – semi dwarfing (M9 – M26) Diploid compact spur type varieties and clones (e.g. Starkspur Golden Delicious)
  2. Medium Vigour- The majority of diploid varieties (e.g. Cox’s Orange Pippin)
  3. Vigorous- The majority of triploid varieties (e.g. Bramley Seedling)

Tree Management Techniques

There is plenty of scope for innovation, especially for the amateur. The following drawings of possible tree shapes and planting systems will stimulate further innovation.

Tree forms

Centre Leader

Diagram
45 degree Plant

Diagram
Stem Loop

Diagram
The Umbrella

Diagram
Zig Zag Stem

Diagram
Tripods
No tree stakes required. Tripod trees withstood the hurricane in Kent without damage. Base of the triangle is 1m x 1m x 1m.
Diagram

Tent
No tree stakes required. Tree vigour can be controlled by reducing or increasing the angle of the trees. Base of the square is 1m x 1m x 1m x 1m.

Diagram

The Curtain
Posts and wires needed for support. This system requires some experience of spur pruning

Diagram

The Combo
Central tree is a Wijcik type pollinator. An alternative is to graft a pollinator variety directly on to the tree.

Diagram

Cox own-root tripod detail3 x Cox’s Orange Pippin own-root trees grown as a tripods to control vigour (1m between each tree) – 1998

Techniques to encourage early cropping

  •  Plant well feathered maidens or possibly 2yr old trees
  •  Plant at an angle of 45 degrees
  •  Tying down branches near horizontal
  •  Summer pruning
  •  Minimum winter pruning
  •  Bark ringing (not in year of planting)
  •  Bending over and tying down leading shoot in late June
  •  Root pruning
  •  Grassing down orchard
  •  Careful use of fertilisers, especially Nitrogen

In general, flowering and harvesting times will be similar to trees grown on MM106 rootstock. Fruit shape will be typical for the variety (MM106 produces a slightly more conical Cox fruit).

The culture of own root trees

  •  The Site The same as for trees worked on a rootstock
  •  The Soil

Own root trees do not require the rich deep soils which are desirable for trees on dwarfing rootstocks. Cox’s Orange Pippin is sensitive to soil pH and will not tolerate a pH below 6.5 and grows better in neutral soil.

The Prejudice Against Own Root Trees

Many Growers have experienced scion rooting in orchards of trees grown on the dwarfing rootstocks M9 and M27. These trees become vigorous as a result of scion rooting and receive hard pruning in winter to keep them confined to their allotted space. This practice causes the trees to grow more vigorously and become unfruitful. The conclusion reached is that trees on their own toots are vigorous and unfruitful, which they can be in these circumstances.

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3 mature Cox’s Orange Pippin own-root trees grown as a tripod

Some research workers, but not all, feel that own root trees are a retrograde step, after all the research that has gone into rootstocks. On the other hand, research work has made own root tree propagation a practical proposition and both England and Europe trial orchards were planted, but cutbacks in research terminated this work. Extended private observations of own root trees has indicated that further development work is worthwhile, especially with organic growing in mind.

Views have been expressed that uniformity of trees on rootstocks is much better. The author has not found this to be correct. Uniform planting material produces uniform trees, whether on rootstocks or own roots.

Years ago, some plum orchards were grown on their own roots and were re-propagated from suckers. This lead to a steady decline due to virus and other diseases, which were little understood by management at the time. With all fruit propagation it is essential to use virus free material whenever possible.

Reliable information from home and abroad has stated that Cambridge Gage used to grow and crop better on its own roots than worked on a plum rootstock. This is now being checked with trees growing on their own roots. Trees of Victoria are also being observed on their own roots.

The Propagation Of Own Root Trees

  • No large scale production of own root trees exists at the present time.

Micro-propagation

This should be the fastest method for large scale production. It has to be carried out with skill and care, to avoid the production of ‘OFF’ types. Trees raised in this way experimentally, have initially been more vigorous and slower to crop than trees from hardwood cuttings. No doubt with more development work these slight drawbacks can be overcome.

Hardwood Cuttings

Variable results have been obtained with hardwood cuttings placed in heated propagating bins. The optimum base temperature has to be worked out together with the air temperature of each variety. For example, Bramley Seedling roots well if cuttings are taken at leaf fall and placed in a propagating bin with base heat of 25° C and in an air temperature of 20° C. Many other varieties rooted with an air temperature around 5° C. There was also marked seasonal variation in rooting. The use of a rooting hormone (IBA) was essential with most varieties. The method is only used for easy rooting subjects commercially, such as rootstocks. New simpler techniques are being evaluated by F.P. Matthews of Tenbury Wells.

Nurse Root Cuttings

This method has proved reliable using M27 nurse roots. Many if not all, varieties can be rooted by this method with or without rooting hormone. Giving base heat in a propagating bin gives speedier rooting, or placing unheated bins under plastic or glass. Placing the cutting bins outdoors can also be successful. This method is used initially to get a variety on its own roots.

Root Cuttings

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The Katy apple tree on it’s own roots, kept to the same size as M9 trees by allowing very heavy cropping.

Roots from preferably young trees, about pencil thickness, can produce a whip about 50cm tall in one growing season in an outdoor bin. Feathered maidens have been produced from roots if the bins are placed under polyethylene or glass. Outdoor benefits from insulation against excessive cold or hot ambient temperatures. Bins are best raised off the ground and placed in good light conditions. It is an ideal method for small scale production.

Propagating Pears, Peaches, Plums and Cherries

The same methods described for apples can be used for pears and plums. The author has limited experience with peaches and cherries. Peregrine peach raised by semi-hardwood cuttings under mist cropped very well indeed. A nurse rooted (using Colt) Stella cherry grew and fruited well. Peach root cuttings from Peregrine tried on a very small scale have not been successful. Roots from Colt cherry rootstocks grow very well.

Future Potential For Own Root Trees

The full potential for own root fruit trees will only be revealed when we have gained sufficient experience of the best methods of propagation and culture. Gaining this experience will be exciting for the dedicated fruit enthusiasts be they amateur or professional. The biggest difference in fruit quality and flavour between own root trees and rootstock trees will be found between own root trees and trees on dwarfing rootstocks.

Trees growing on their own roots may not crop more heavily or have better fruit size than trees on M9 although better cropping and fruit size has been apparent with some varieties. What can be virtually guaranteed with the experience gained so far, is more regular cropping and better quality fruits which have a better storage life. Fruit flavour could well be more intense and with generally more seeds per fruit, better fruit shape. In the end it will be the grower who by his skill, can manage own root trees and obtain the full potential.

Pruning Guide for Own Root Apple Trees

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Cox’s Orange Pippin own-roots trees grown as tripods to control vigor

The vigor of an own root apple tree depends on the variety or clone, not on a selected rootstock. The best way to control the vigor of an apple tree, whether on its own roots or a rootstock is by cropping.

The basic vigor range of rootstocks is:

  1. Dwarf – semi dwarf Rootstocks M27, M9 and M26
  2. Medium vigor Rootstocks MM106, M7 and MM111
  3. Vigorous – very vigorous Rootstock M2, M16 and M25

The vigor of named fruiting varieties can also be grouped into three categories:

The vigor of named fruiting varieties can also be grouped into three:

1. Dwarf – semi dwarf

  • All Wijcik (Ballerina) varieties
  • Starkspur Golden Delicious
  • Granny Smith Spur
  • Lord Derby Spur (culinary)
  • Sunburn
  • Cox Spur Type
  • Discovery Spur Type

2a. Medium vigor (Dessert) mainly diploid varieties

  • George Cave
  • Discovery
  • James Grieve
  • Worcester Pearmain
  • Lord Lambourne
  • St. Edmund’s Pippin (russet)
  • Cox’s Orange Pippin
  • Sunset
  • Golden Delicious
  • Winston
  • Pixie
  • Sturmer Pippin

2b. Medium vigor (Culinary) mainly diploid varieties

  • Early Victoria
  • Grenadier
  • Rev. W. Wilks
  • Arthur Turner
  • Golden Noble
  • Bountiful
  • Lane’s Prince Albert
  • Annie Elizabeth
  • Edward VII

Vigorous – very vigorous -mainly triploid varieties

  • Blenheim Orange
  • Bramley Seedling
  • Crispin
  • Jonagold
  • Jupiter
  • Newton Wonder
  • Orleans Reinette
  • Ribston Pippin
  • Suntan

Pruning apple trees

This is carried out in two stages.

1.At planting time to train the tree to grow into the desired shape.

  • ◦ Pyramid and Spindle Bush
  • ◦ Bush 3′ leg
  • ◦ Half standard 4 1/2′ leg
  • ◦ Standard 6′ leg
  • ◦ Centre Leader
  • ◦ Cordon
  • ◦ Espalier
  • ◦ Fan
  • ◦ Tripod (three trees)
  • ◦ Step over

3. Growing tree

  • ◦ To let light and air into mature trees to encourage flower buds,
  • strong mature flowers and good quality fruit.
  • ◦ To cut out damaged or diseased wood.
  • ◦ To regular cropping by removing excess fruit buds especially by
  • thinning complex spurs.
  • ◦ To renew branches.
  • ◦ To retain a balanced (stable) tree.
  • ◦ To allow access for picking fruit.
  • ◦ To maintain tree in space provided.

FAILURE to prune mature trees will lead to:

  •  Tangled and overcrowded growth.
  •  Excessive cropping which increases the risk of biennial bearing.
  •  Excessive shading causing small, inferior quality fruit.
  •  Difficult to pick fruit.
  •  Increased pests and disease.
  •  Harder to get good spray cover.
  •  More likelihood of unbalanced growth leading to a greater risk of tree
  • instability, especially when carrying a heavy crop.

Growth characteristics of apple trees

Two kinds of buds can be found on apple shoots/branches. On one year old shoots there will be small wood buds. In the second year some wood buds will fatten up and become fruit buds. The terminal bud at the end of the shoot will normally continue the shoot extension although in a few varieties (tip bearers such as Worcester Pearmain) the terminal bud will often form into a fruit bud, and fruit in the 2nd year. In the third year flowers will emerge from the fruit buds and if pollinated successfully, the flowers will grow into apples.

The fruit buds on two year old wood are in reality very short shoots calledspurs. Some varieties called spur types grow further spurs as the apples are growing, instead of shoots. Normally each spur will terminate in a fruit bud. After a few years the spurs become numerous and the quality and size of fruits formed on them deteriorates due to competition. It is then necessary to thin the spurs in the winter, so that competition is reduced. Apple varieties forming spurs readily are the easiest to manage on their own roots, as much as of the natural tree vigor foes into the production of apples. All the other varieties need to be pruned to encourage a good balance between growing and fruiting.

Time of pruning and effect

Winter

Pruning in winter reduces the aerial parts of the tree but not the roots. The effect will be to increase the vigor of shoots and branches and discourage formation of fruit buds. Winter pruning is ideal for trees that have too many fruit buds and little extension growth. Pruning young trees where growth is needed and directed in to forming the tree, rather than fruit production, is carried out in winter.

When the trees are leafless in the dormant winter season, damaged, diseased or congested growth can easily be seen. If the tree is very vigoros, winter pruning is less desirable. In this case it is best to leave pruning until growth in the spring starts, or prune directly after picking and before leaf fall.

Summer pruning

At this time of year, pruning reduces the number of leaves which manufacture food materials. Summer pruning therefore reduces the vigor of the tree and improves the cropping potential. Summer is an ideal time to remove strong vertical shoots which are generally unfruitful and shoots growing underneath branches which get heavily shaded.

Pruning – apical dominance

The highest bud on a shoot, pruned or unpruned will be dominant and will grow out stronger than any other bud. The strongest growth will be at the top of a branch or tree. When growing a centre leader tree (a tree with a central trunk up to the leading shoot) you control growth using the leading shoot of the stem. Cutting back the leader will increase growth in the lower branches. Leaving the leading shoot unpruned will reduce vigor in the lower branches. The harder the tree leader is pruned (ideally down to a well placed weak shoot) the greater the vigor increases in the lower branches.

Pruning methods

Pruning is best demonstrated in the orchard. Failing that, watch the response of the tree to pruning and react accordingly.

Regulated pruning

This is exactly what it says. Pruning to regulate the tree growth and cropping. Basically a tree is pruned to get balanced growth and branches to carry fruit in good light and air. Vertical growing vigoros shoots are usually unfruitful and shoots growing downwards underneath a branch get heavily shaded, both types should be removed. Shoots growing out from the sides of branches are ideal for carrying fruit. When these side shoots have grown too long they are best cut back to the main branch with a sloping cut, leaving more stub underneath to encourage a renewal shoot to grow from the stub at a nice wide angle.

The basic bush tree and centre leader tree should have about four main branches, arranged around the tree for good stability. The height of these branches from the ground will depend on the type of tree being grown. Bush trees have branches around 3′ from the ground, half standards 4 1/2′ and standard trees 6′ from the ground. Centre leader trees normally have their main branches at waist height for easy harvesting of the fruits. Branches above these are renewed before they get too big, by cutting them back to the trunk with a sloping cut to avoid too much shading of the main branches.

Spur pruning

This method of pruning is mainly used for cordons, espaliers and other more formal shaped trees. The object is to create fruiting spurs close to the stem and main branches. Some varieties form spurs very easily (Starkspur Golden Delicious) and are known as spur types whilst others range from easy to difficult.

The difficult varieties are usually tip bearers (e.g. Worcester Pearmain) and vigoros triploid varieties (e.g. Bramley Seedling). Spur pruning is mainly carried out in the summer and involves cutting back shoots growing directly from the stem or main branches to encourage fruit buds to form near the stem or branch. There are many ideas about how best to achieve fruiting spurs close to a stem or branch. The vigor of the tree can be used as a guide.

Weak growing trees

Prune young shoots when they reach 9″ and cut back to an underneath bud around 6″.

Moderate vigor trees

Prune young shoots when they have reached 12″ back to an upward growing bud around 9″. The shoot will almost certainly grow out from that top bid and can later be pruned back to the underneath bud behind the top bud which has grown out at a better angle.

Vigorous trees

he-cox-single

Orange Pippin Own-Root Trees, 1987

Prune young shoots that have reached 18″ back to top bud around 12″ then continue as for medium vigor trees. This can only be a rough guide and timing will differ due to weather, culture etc. Watch the tree’s response to pruning and adjust accordingly. Ifthe tree has not responded with fruit buds near stem or main branch it is best to cut the shoot back to the stem or branch with a sloping cut to encourage a further shoot to grow out at a wide angle and start again.

Grafting shoots into strategic positions

If all else fails, there is a graft that can place a shoot in a branch or stem, provided the stem or branch is reasonably thick. This involves collecting dormant one year old shoots in early February and placing them upright in a pot of sand to a depth of 4-6″ which is then placed in a cool shady part of the garden. Alternatively, shoots can be placed in a polythene bag (not airtight) and stored in the vegetable compartment of a refrigerator. In April when the sap rises and the bark will lift, the stored shoots can be used for slit grafts in the bark. This enables shoots to be placed in ideal positions on stem or branch. Length of grafts depends on the vigor of the tree. 4″grafts for weak growing trees, 6″ for moderate vigor trees and 8-9″ for vigorous trees. These grafted shoots normally form fruit buds easily.

Pruning should not be regarded as an isolated operation but as part of the tree culture and taken together with soil management and cropping. For more detailed information about pruning, the R.H.S. Wisley Handbook on Pruning Hardy Fruits by Jack Woodward can be highly recommended.

H.F.Ermen. A.H.R.H.S., N.D.H.

Mr Ermen died in 2009. In March 2010 the UK Royal Horticultural Society recognised Scrumptious, one of the most popular varieties raised by him, with the Award of Garden Merit – the first such award given to an apple variety for more than 10 years.