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.

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Triploid Apples: An adventure into their history, breeding and use

One of the most important considerations to me when growing apples in the South is if the cultivar has a tolerance to pests and diseases. Called “the final frontier” by my Northern and Western apple growing friends, the Mid-Atlantic and the rest of the US South are notoriously difficult areas to grow domesticated fruit. In true Southern hospitality, our soupy humidity and hot temperatures not only extend a warm embrace to all sorts of pest and disease here, but invite them to stay for a long while and breed.

Despite this high diversity of fungal, bacterial and insect pressure, there are still old apple trees in the landscape that have survived decades upon decades of environmental assault. These trees have been the subject and target of much interest in my network of fruit explorers, as these specimens are proof that it is possible to grow purposeful fruit and trees in this landscape without toxic, self-perpetuating inputs. In past essays, I’ve discussed rootstocks being a factor in this, where larger root systems tended to produce healthier trees.  But there are more factors in resilience than just the root system. In today’s essay, which has literally been in my drafts for 3 years, I want to discuss something I’ve been casually studying for years: Polyploidy, or having more than 2 paired sets of chromosomes.

Screen Shot 2019-05-26 at 8.32.23 PM.png

I’ll begin with a bit of history. In the early 1900s, there was a Swedish plant breeder and geneticist named Herman Nilsson-Ehle, who had spent much of his professorial career breeding wheat and oats for high yields in Sweden. He was a huge fan of Gregor Mendel, who had released his findings on inheritance only 8 years prior to Nilsson-Ehle’s birth, and his whole outlook on plant breeding research was a hat tip to Mendel. Mendel, for those of you who may be struggling to remember, was the Monk who stared at pea plants and developed the fundamental laws of inheritance, which we encountered in high school biology as the punnett square .

Before I go any further, I want to give a quick warning. From my research on Nilsson-Ehle, it appears he was a fan of “new Germany,” and saw the genetics research under Hitler’s regime as a means to save the world. In order to only showcase the apple breeding aspect of this man, I’m not going any further in this subject. If you want to read more on his thoughts, which scarily echo modern times, you can go here: Lundell 2016

In his early research of breeding cereal crops, Nilsson-Ehle would sometimes observe natural mutations in the hundreds of thousands of seeds he planted out for observation. These mutations had much larger, rounder leaves and after poking and prodding these mutants, he discovered their large size was due to having 2 additional sets of chromosomes, or polyploidy (Usually a diploid (2 sets of chromosomes), these plants were now tetraploid (4 sets of chromosomes). These plants exhibited giantism in all ways aside from vigor (which was relatively low). While the leaves and shoots were much thicker than diploids (2 chromosomal pairs), the flowers, fruits and seeds were nearly double in size. This was remarkable to Nilsson-Ehle and prompted him to theorize: If I take this mutant tetraploid and cross it back with its diploid self from the same cultivar, I should get a triploid (3 sets of chromosomes) that brings about enhanced genetics of both! 

screen-shot-2021-07-29-at-6.43.41-pm

He was right. The tetraploids he crossed with diploids produced triploids that were more vigorous, hardy and resistant to disease than their diploid or tetraploid counterparts due to enhanced genetic modifiers inherited from the parents of two different ploidy (tetraploid and diploid). This brings me back to fruit exploring in the Mid-Atlantic and Southeastern US. The large majority of US cultivars known today as being able to tolerate fireblight, apple scab, powdery mildew, and loads of other issues while still persisting in the Southern landscape for decades upon decades are triploids! Including the Dula Beauty, my sturdy family apple cultivar.

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So the US picked up on Nilsson-Ehle’s breeding work and adopted it to their work in the states to breed for hardy, disease resistant apples, right? Nope. WW2 happened and we were already distracted with breeding for scab resistance (more about that in a bit). In 1950, famed berry breeder George Darrow reported on Nilsson-Ehle’s work in an address to the American Horticultural Society. In this address, he mentioned the premise behind Nilsson-Ehle’s work and connected the dots in how this way of thinking has translated into berry breeding for larger, higher quality cultivars. He briefly mentioned apples in this address, reporting that a tetraploid sport (mutant) of McIntosh had been found growing on branches of a normal McIntosh tree in New England, but the mutant branch was only half tetraploid, as the cortex of the wood was diploid (making it a ploidy chimera). He said they were trying to stabilize the McIntosh chimera as a full tetraploid through tissue culture, and I believe they achieved this due to the photo below. This was the end of an interest in sustainable fruit breeding in the US, in my grumpy opinion.

Screen Shot 2019-05-18 at 9.34.40 AM

Come on, Eliza, what about the Liberty apple? Goldrush? RedFree? Prima? [Slight rant/history on apple scab. Skip to below scabby apple pic to avoid]. Sure, there was a breeding effort between selected US land grant universities (PRI= Purdue, Rutgers, Univ. of Illinois) that began in 1926 to create scab resistant apples. They succeeded in doing so in a basic sort of way, which eventually led to the downfall of this research.  The style of their research was “monogenic,” or relying on a single gene to control scab resistance in an apple cultivar. There was also a whole lotta inbreeding going on.

The gene identified to have scab resistance is called the “vF gene,” which comes from the cultivar “Malus floribunda 821.” The reason why they picked this gene is because they could identify it in seedlings using molecular markers, so they didn’t have to waste time growing the trees to find out if it was scab susceptible or not.  That worked out well enough for a while and they selected some ho-hum cultivars (minus Goldrush, which is awesome but incredibly prone to cedar apple rust) to make available to the public. In 2002, the first reports of scab infection were reported on the scab-resistant apple cultivar ‘Prima.’

In 2011, a German pomologist wrote an article about all of this and, thankfully, it was translated into English shortly thereafter. What he found, looking into the lineage of most US and Euro scab resistant apple cultivars, was a huge amount of inbreeding going on. Not only that, but the cultivars being crossed back to themselves were highly susceptible to scab! I’ll quote directly from the article:

“Today the global fruit breeding industry is producing a wide range of varieties, with one big difference: the overwhelming majority are descendants of just six apple cultivars.

The author’s analysis of five hundred commercial varieties developed since 1920, mainly Central European and American types, shows that most are descended from Golden Delicious, Cox’s Orange Pippin, Jonathan, McIntosh, Red Delicious or James Grieve. This means they have at least one of these apples in their family tree, as a parent, grandparent or great-grandparent…” 

Many of the PRI releases have these 6 cultivars crossed multiple times in their lineage. If you do this right and bring out the right traits without problems, it’s called ‘line breeding’. If you end up with problems, it’s called ‘inbreeding’.

The second and main problem with this breeding work, in my opinion, was in our complacency with our selections. We basically ignored any further breeding efforts for scab resistance in order to pursue “Crisp” apples. Takeaway message: FEEL GUILTY ABOUT EATING A HONEYCRISP, COSMICCRISP, CRIMSONCRISP KARDASHIANCRISP ETC. BECAUSE THATS WHAT BREEDING LOOKS LIKE NOW INSTEAD OF BEING ABLE TO GROW APPLES WITHOUT MAJOR INPUTS! Too bad we haven’t been thinking about triploids or even multiple-gene scab control for the last 50 years.

Screen Shot 2019-07-14 at 2.00.30 PM.png

Guess who has? Russia. 

Since the early 80s, the All Russian Research Institute of Fruit Crop Breeding (VNIISPK) has continued with the scab resistant vF breeding work that spread across the US and Europe, only it is way more badass. Not only are they breeding for scab resistance, but they’re breeding for tolerance to late frosts, consistent yields without having to thin fruit, COLUMNAR growing habit AND Nilsson-Ehle’s version of triploidy (Speak a little more into my dirty ear, Russia). However, the near-sensationalism of these claims doesn’t stop there. Dr. Evgeny Sedov, the primary researcher in this endeavor (and someone I would really love to interview), closes the abstract of one of his scientific papers that goes into his triploidy research with the following that is so, so Russian:

“It is noted that triploid apple cultivars developed at VNIISPK are inferior to none of the foreign cultivars, based on a complex of commercial traits, and they significantly excel foreign cultivars in adaptability. Our apple cultivars may contribute to the import substitution of fruit production in Russia.”

Some mentioned and additional benefits of triploids (Or reasons to pursue more polyploidy breeding):

  • Adaptability to climate, disease, stress: In the above quote, Sedov writes how his triploid apple cultivars significantly kick other apple cultivar ass in terms of adaptability. And based on my research covering the last 100 years, he’s not wrong. There have been many observations by the scientific and lay community reporting that triploids end up being more cold hardy, more heat tolerant (the thickness of leaves and fewer, larger stomata give rise to a lower transpiration rate and more water retention that can be used during drought), have better nutrient uptake, and improved resistance to insects and pathogens. The theory for triploids having a higher environmental adaptability has to do with  an increased production of secondary metabolites, which enhance plant resistance and tolerance mechanisms (as well as chemical defense).
  • Thinning: Triploids often have low fertility due to a reproductive barrier of having an extra set of chromosomes- making pollination difficult. Some apple pollen tends to pair decently well with triploid apples to get a decent crop. With most cultivars it isn’t great- just good. This could be seen as a boon to this class of ploidy, but I see it as a good thing. One of the greatest challenges to organic apple production is the thinning process. Most non-organic orchards thin using chemical sprays to knock off flowers or fruits. To this day, many organic spray chemicals either do a lackluster job, or oh-god-that’s-far-too-many-job of thinning the fruitlets off, leaving many orchardists to either thin by hand or accept biennalism (which was a 3 hour conversation at Stump Sprouts one year). If you have healthy pollinator populations, less fruit on the tree will guarantee you a return crop the next year, barring other environmental catastrophes (which you’re better prepared for with triploids, anyways).
  • Vigor: In the past, I’ve written about vigor on the Elizapples.com blog and how it’s my number one enemy in the Mid-Atlantic given my heavy soils, warm temperatures and ample water supply. Though I need to revisit those essays and condense them into my current evolution of thought, the reason for my past concerns around vigor is that I have conditions that induce [what I’d like to think is] “artificial vigor.” In my climate, this shows up as extreme vegetative growth, which sometimes gives rise to heightened fireblight pressure and other vulnerabilities. Though “artificial vigor” is likely what an incompatibility of growing conditions looks like, I’ve started to differentiate it from what I’m calling “true vigor,” or youthfulness through heterosis/hybrid vigor. This is where triploids shine.

    When you start digging in old texts, back before the rise of clonal rootstocks, you might encounter mention of two classes of trees referred to as “Standards” and “Fillers.” The “standards,” often mentioned as Baldwin and Rhode Island Greening (both triploids) were larger trees that took longer to bear fruit. These were thought to be permanent trees, or trees that would be around for generations. The “fillers,” such as Yellow Transparent and Wealthy, produce much smaller trees in the same length of time and were far more precocious in bearing fruit. These trees were thought to be temporary, and were planted in between the “standards” to increase production in the early life of the orchard. An unfortunate modern day “filler” would be HoneyCrisp (diploid). Growing in my climate, it is better termed runtycrisp. Super low vigor, gets loads of diseases, precocious bearer, dies early. Sort of an orchard mercenary. This, to me, is a good way to think about vigor. If you’re growing for the long-term, you’ll want a truly vigorous cultivar that teems with youthful energy, and I believe that youth is heightened as a triploid. If you are growing in areas that are full of pest and disease, it is also not a bad idea to have an extra set of chromosomes to help with defense and stress. Relic trees standing tall in the South tend to be triploid and their presence speaks to their youth and defense: Arkansas black. Fallawater. King David. Leathercoat. Roxbury Russet. Stayman Winesap. 

    With all of this said, we have a lot of work ahead of us to start thinking about what our breeding programs would look like if we set our targets on low-input, no spray, multi-gene disease tolerance and more. I get it, HoneyCrisp can store for a calendar year in my crisper drawer, but that’s all it has going for it after a year in there.

    I am pulling for the expansion of ‘process’ industries such as hard cider, vinegar, juices, syrups, etc to become the targets of agroforestry planning and planting enterprises in the near future. Annual or livestock farmers don’t want to mess with sprays or inputs that are outside of their normal non-tree crops care. If they are going to receive incentives to plant trees on their farms, they will want the ones that need little care and have an economic outlet. This will require a new set of apple cultivars to choose from and they have to come from somewhere…

     

Here is an incomplete list of confirmed triploid apples. Many of these are from the UK and do so-so in my climate. The ones with asterisks are what I have seen as old relic trees in the Mid-Atlantic:
Arkansas Black*
Ashmeads Kernel*
Baldwin*
Belle De Boskoop
Blenheim Orange
Bramley’s Seedling
Buckingham*
Bulmers Norman
Canadian Reinette
Catshead
Close
Crimson Bramley
Crimson King
Crispin
Dula Beauty*
Fallawater*
Fall Pippin*
Frösåker
Genete Moyle
Golden Reinette von Blenheim
Gravenstein*
Hausmuetterchen
Hurlbut
Husmodersäpple
Jonagold
King David*
King of Tompkins County
Lady Finger
Leathercoat*
Margille
Morgan Sweet*
Mutsu
Orleans Reinette
Paragon*
Red Bietigheimer (Roter Stettiner)
Rhode Island Greening*
Ribston Pippin* (struggles with brown rot)
Roter Eiserapfel (Has 47 chromosomes rather than 51)
Rossvik
Roxbury Russett*
Shoëner Von Boskoop
Spigold
Stäfner Rosenapfel( Has 48 chromosomes)
Stark
Stayman*
Stayman Winesap*
Summer Rambo*
Suntan
Tom Putt
Transcendent Crab
Transparente Blanche
Vilberie
Vixin Crab
White Astrachan*
Winterzitronenapfel
Winter Pearmain
Washington Strawberry

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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

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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.

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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.

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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”

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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. 

 

 

 

 

Rootstocks: Do they impact flavor?

Earlier this year, as I was doing some research on the effects of grafting apple varieties to Malus angustifolia (southern crabapple), I kept running across interesting accounts of noticeable changes to the apple varieties when grafted to crabapples. One of these changes is in flavor, which is what I’m writing about today.

This is the original snippet that sparked my interest. Why? Because this dude back in the 1800s is telling me that when he took the Bethlehemite apple, a dessert/culinary apple from Ohio, and grafted it to a crabapple rootstock, he got something different from the original variety. The grafted Bethlehemite apple had developed some astringency. Astringency is the key word here.

OMG, DID THIS GUY TURN A DESSERT APPLE INTO A CIDER APPLE BY GRAFTING IT ONTO A CRAB ROOTSTOCK?

This thought has rumbled around in my head for the better part of this year and whenever I had a moment to sit at the computer and not read my emails, I researched this topic a bit more. First, I went back in history (via google books) to find more testimonials of these findings. Here are a few:

1867:

1871:

1873:

1889:

 

I could go on, but there are many, many testimonials in favor of rootstock having a flavorful impact on the grafted variety. There were some naysayers, who basically just said “this can’t be so” and changed the subject. But all in all, my historical research has been in favor of a rootstock’s ability to change flavor in apple varieties.

Eager to pursue this topic, I started looking up scientific papers on the subject and started with this, Cornell’s research on nutrient uptake by different rootstocks.  The thoughts and questions of the horticulturalists back in the 1800s seem to still align with the questions of today, as seen in this conclusion:

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“The ability to match the nutritional requirements of a scion cultivar to a specially tuned rootstock…” COULD, in my opinion, create a cider apple out of a friggin’ dessert fruit.

Positive, I kept up the research and found considerable evidence in citrus fruit that rootstocks can change the flavor of the fruit. Here. Here. And Here.

This study, which looked at an apple rootstock’s impact on triterpene (cancer and immune disease prevention chemical compounds) found this:

“The largest differences in triterpene content were found between rootstocks. The results showed that both at harvest time, and after cold storage except the first harvest time samples, the apples from rootstock MM106 had significantly higher triterpene content compared with those from M9; … Selecting suitable rootstock might increase the triterpene content in apple peel in practice production.”

And this study on different rootstock’s impact on peaches showed that the variety ‘Suncrest’ on Julior (rootstock) and GF677 (rootstock), followed by Ishtara (rootstock), produced fruit with the greatest antioxidant activities and total phenolic contents. The ‘Suncrest’ on Citation (rootstock) and, especially, Barrier1 (rootstock) had reduced nutritional values of the fruit.

WHAT DOES THIS ALL MEAN? 

Right now, everyone I know who is planting a cider orchard is planting on known rootstocks like the MM series or the Geneva $eries. With these rootstocks, we know what size of tree we’ll get and we generally know when it will start cropping apples. This is valuable information because we want order and sense in our orchards. We also know the disease tolerances of each rootstock, which have been known to convey some resistance to the apple scion, and that’s all well and good. There are many knowns of these rootstocks because they’ve been extensively studied…for dessert fruit. But what about cider fruit? How many rootstocks have been thrown out in university trials for imparting astringency to an apple? Probably a lot. But what if this is what we’re after?!

If someone came to my farm peddling their wares and told me that they could take my dessert apple and turn it into a cider apple with one of their amazing magical rootstocks, I would buy it. I’m sure it would be a hit. This is why we have started in on the private research of grafting apple varieties to different rootstocks for the purpose of flavor/nutrient evaluation (as well as growth influences, which is another blog entry).

Currently, my partner and I have Malus angustifolia (southern crab), Malus baccata (Siberian crab), own-root, M7 and M111 trees grafted in our nursery to the same variety. These will soon get planted out at the farm in an area set up for evaluation. This, I believe, is another untouched frontier whose findings could be incredible for the future of growing superfruits, having value-added rootstocks, and growing with lower inputs.

So far, the science and the observations are there. There’s much more to learn, but why not start in on the fun?

 

Ugly Fruit is Especially Nutritious

And this spin off from Jill Neimark’s NPR piece just happened, this time in Food&Wine!

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By James Oliver Cury Posted April 27, 2016

Bruised and scabbed apples have more antioxidants and sugars because they’ve fought off natural stressors.

Grocery shoppers don’t generally make a beeline to the scabbed and blemished apples. But maybe they should. New research shows that trauma to the fruit—stresses from fighting heat, bugs, and fungus—forces apples to produce antioxidants such as flavonoids, phenolic acids, anthocyanins and carotenoids. And these compounds have all kinds of nutritional value.

Click here to read moreContinue reading

Nature’s Secret: We May Have Totally Underestimated Scarred Fruit

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A spin-off article from yesterday’s NPR article on eating ugly fruit, this time on weather.com! I’m so psyched this is getting attention. It’s only the beginning!!

Let’s face it: ugly fruit gets a bad rap. It’s often left behind at grocery stores and sold at steep discounts at farmers markets. More often than not, it gets tossed on top of an ever-growing pile of wasted produce.

But it turns out, these ugly fruits are fine to eat – and they may even be more nutritious.

 

Read more: Here!