In Defense of Bradford Pear

I wrote this article for TheFruitExplorers.com and decided to cross post it here.

Every year, around this time, social media begins to rumble in uproar over Bradford Pear (Pyrus calleryana). With headlines like “The Curse of the Bradford Pear,” “Bradford pear tree: How the trees can hurt people, then environment,” and finally “I Just Hate Bradford Pear,” it’s no wonder people have it out for them. The trees have NO GOOD PRESS and, unfortunately, it’s much easier for hoards of people to fall in line with anti-invasive rhetoric than to understand who or what they are trying to demonize. In light of this, the time has come to take a stand for this poorly misunderstood tree.

Bradford pear belongs to the species Pyrus calleryana, which is why it is sometimes called “Callery.” This species of pear is native to China, where the range goes from sea-level to 5000 feet in elevation, spanning a thousand miles inland as the crow flies. Cousins of callery pear are also in Northern Korea and Japan, showing an immense climate and site adaptability for the species.

Pyrus calleryana in Japan
Pyrus calleryana in Japan

How did it get to the US?:

In the early 20th century, the Pacific Northwest contained many orchards of Pyrus communis, or French pears. These pears were being ravaged by fireblight (Erwinia amylovora), a native bacterial disease, and professor Frank Reimer was pulling his hair out over the potential loss of the West Coast commercial pear industry if a control for fireblight wasn’t found soon. Researchers have long known that Asia’s gene pool for fruit and nuts is much older than European or American genetics, and likely hold resistances or much improved tolerances to pest and disease due to the long and slow co-evolution over time. Reimer knew, from his research, that Pyrus calleryana and Pyrus ussuriensis were inherently resistant, so he put out an SOS to obtain pear seed from Asian regions in order to hopefully find resistance.

Professor Frank Reimer, left
Professor Frank Reimer, left

Harvard’s Arnold Arboretum in Massachusetts answered his call in 1908, sending plant explorer EH Wilson (aka “Chinese” Wilson) to China to see what he could find. Once there, he collected P. calleryana seeds from 4,000-5,000 feet in elevation and sent them to be grown out in Boston. Many of these proved to be hardy for Massachusetts and many people, including professor Frank Reimer, got excited. Given the potential for Pyrus callerana to save the commercial pear industry in the PNW, the USDA decided to add callery pear to their fruit’s explorer’s collection list.

At the time, the USDA had been going through a period of glitz and glam concerning their plant exploration program. The golden child at the center of this hubub was the darling plant explorer David Fairchild, the person responsible for bringing over German hops, the avocado, and kale (among many, many other things). With his notoriety and prestige, he married into the fabulously wealthy family of Alexander Graham Bell, and was feeling the need to step down from his travels abroad in order to start a family. Instead of Fairchild himself going on the pear mission, he delegated the job to one of the toughest mofos alive: Frank Meyer. Dutch born, Meyer was known for his ability to walk 30+ miles a day, everyday, forever.

Frank Meyer in Turkestan
Frank Meyer in Turkestan

This would be no small job, either. According to Arnold Arboretum, 25 pounds of seed would require picking seeds out of 5000 pounds of fruit. That’s the equivalent of 125 bushels of tiny (8.5mm on average) callery pear fruits, which would be maddening to collect by hand. This wasn’t a problem for Meyer, though, as he probably preferred tiny pear seeds to interacting with people. With his marching orders, he set out on this pear mission, writing the following to his boss, David Fairchild:

A letter to David Fairchild from Frank Meyer April 16, 1917
A letter to David Fairchild from Frank Meyer April 16, 1917

Once the first batches of seeds were back in the States, they went under commercial pear rootstock monitoring for fireblight resistance. These pear seeds produced vigorous, uniform trees that, when inoculated with fireblight, proved to be the most resistant of any pear tree they had evaluated, by a landslide (double the resistance of Pyrus ussurriensis and far more vigorous). The chart below reveals the results of this trial:

Fireblight Results Callery Pear Innoculation.png

In later studies, Reimer reported that 11% of P. calleryana trunk inoculations showed a severe fireblight infection. Which, by the way, is pretty amazing. When I innoculated my apple seedlings with fireblight ooze, 95% of them showed severe infection or died.

In addition to having stellar fireblight resistance, Callery pears were tested on a variety of sites and were found to thrive in nearly all soil and moisture scenarios, from coarse sand underlain by granite to heavy clay. They also found Callery pears to have a lower chilling requirement than P. communis (French pear rootstock) (source), allowing for it to be grown in more erratic seasonal conditions (which might not have been a big deal then but MAN is that a big deal now). This pear species was seen as the most bomb-proof, resilient rootstock around on which to grow our favorite eating pears, and even produced yields 32% above the same cultivars grafted to P. communis (Source: Westwood, Pear Rootstocks for the Northwest. NAFEX POMONA Vol 3, Number 2, 1970). With the excitement and growing popularity of using callery pear as rootstock, the US continued with seed gathering trips to China for decades.

From Amazing to Pariah, what happened?

First of all, most of what you read about the introduction of Bradford pear (P. calleryana) to America is incorrect, as I’ve just given you the real history above. Outlets like The Grumpy Gardner, a now-retired columnist for all things horticulture at Southern Living Magazine, have done a lot of damage spewing emotion-based information to people who don’t know any better.  With little challenge to any of the points ever made, he and others managed to create a culture of emotional reaction surrounding P. calleryana, rather than a much needed practical one. For the record, the chances of you being allergic to Bradford Pears are slim to none because they aren’t wind pollinated. Bullied, bruised, blamed and constantly soaked in toxic agri-chemicals to try and kill it, the Callery pear is one of the most shamed species in the US. If you don’t believe me, look no further than the hundreds of online articles that alone focus on how the blooms smells like male ejaculate (that’s spermadine and putresine you’re smelling and it’s in a lot more plants than you think, including the beloved American chestnut).

Why didn’t Callery become the main rootstock of all pear production in the US? According to Reimer, on average, the tree isn’t very hardy (doesn’t like to grow colder than 7a, or below -10 fahrenheit), it doesn’t propagate all that well from stooling beds (primary means of producing rootstocks in the nursery industry), and has poor fruit qualilty. Why fruit quality matters for a rootstock is beyond me, but it was listed as a reason. In regions 7a and hotter, though, Callery pear is the best rootstock onto which one could graft European and Asian pear cultivars, but the research conducted on these pears was West coast centric and never really made it over to the East, even after Callery became a dreaded invasive.

Root Stock to Ornamental to Monster:

The Glenn Dale Maryland USDA research site had planted many P. calleryana seeds from Frank Meyer’s collection and by 1950, there were still a few P. calleryana trees remaining at the location. In 1952, researchers took notice of one particular thornless (many wild apples and pears have thorns) tree with an amazing white bloom (Callery produces fruit on lateral branches, on the previous year’s wood and on spurs of older wood. According to Reimer, It probably produces more blossoms than any other species of Pyrus). Thinking this could be of ornamental quality, cuttings were taken from this tree, grafted onto a seedling Callery pear rootstock, and planted in a subdivision nearby for testing. These trees were pruned/maintained, and after 8 years of oohs and ahhhs, they named the cultivar ‘Bradford,’ in honor of the horticulturalist who recognized its potential as an ornamental tree.  By 1962, the Bradford Pear was available commercially and it became one of the most widely planted suburban trees in the US.

Around this time, other research stations and arboretums were noticing the ornamental value of the seeds planted from Meyer’s explorations. The National Arboretum produced, from a seedling selection, a cultivar called “White House,” and a seedling now known as “Autumn Blaze” was selected from the Horticultural Farm in Corvalis, Oregon.

The late 1960’s welcomed a gold-rush era of Callery pears, with many nurseries planting out seedlings from the original collections of Frank Meyer in order to find the next Bradford. This, friends, is where we start to transition from Amazing Rootstock to Amazing Ornamental Street Tree to “The Curse of the Bradford Pear.”

Pyrus calleryana is amazing for all of the reasons I listed above (insect and disease resistance, able to grow in a variety of soils and climates), but did you know it is also largely resistant to pest like deer, Japanese beetles, and wood boring beetles? The tree is precocious (often 3 years to fruit), the first to leaf out in the spring and the last to drop its leaves in the fall/winter. All of these qualities are noteworthy, yet have gone largely unnoticed due to one thing: The original ‘Bradford’ tree was self sterile.

When a tree is self-sterile, it cannot reproduce with itself in order to create progeny (fruit with viable seed). This wasn’t a problem when Bradford clones were planted out in the DC suburbs, because they were all genetically identical. When the bees would visit the flowers of one tree, and then the next, the pollen was sterile and did nothing to further fruit development.  However, that was just one cultivar’s genes.

Remember when I said that Meyer walked 30+ miles a day? He covered so much ground while in China that he sent seed from Callery pear populations hundreds of miles apart. As it turns out, these populations produce genetically distinct cultivars under the species, and are totally able to cross with one another. Which they did once all those populations were brought together to intermingle in the US.

When the other ornamental selections like “White House” and “Autumn Blaze” showed up on the streets, the self-sterile Bradford pears soon became promiscuous in the neighborhood. By 1980, 300,000 Callery pear trees had been planted as street trees, producing huge amounts of small fruit with viable seed. From there, seedlings spread far and wide via birds and raccoons.

Today, in certain areas of the US, Callery pear seedlings can be found inhabiting fence-lines and ecologically stressed out pastures/roadsides, causing everyone to scream INVASIVE! THEY’RE INVASIVE! OMG KILL THEM. I CAN’T EVEN THINK STRAIGHT RIGHT NOW. EWWWW. IS THAT SPERM I SMELL? KILL.

But let’s take it out of all caps for a moment and go a bit deeper, because they deserve a chance.

Why is it so successful in the landscape?

Look, when you get into research about exotic plant species in the US, a huge majority of papers are biased in their research scope to focus on their invasiveness rather than what they offer. For instance, this paper (and there are many like this) decided to go ahead and only name one bird, the invasive European Starling, as being responsible for spreading callery pear in the landscape.

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This is a type of fear mongering that I find over and over again. Rather than list the native birds that actually feed on Callery pear (there are MANY), research tends to dwell on the negative ones in order to further demonize this tree. I’ve been writing this paper for nearly 3 years (because 2 editions of this have been deleted on accident) and the only research I have been able to find listing native birds comes out of non-profit research and a masters thesis from Michigan, both BURIED in google. Over time and with much frustration given the extreme biases of US research, I decided to broaden my search for Callery pear dispersal in other countries, and the following is what I found out of Australia:

Size of fruit matters given the diversity of birds.
Size of fruit matters given the diversity of birds.

As you can see from the diagram above, the size of fruit directly corresponds with the number of frugivorous bird species that eat them. Like most ornamental fruit trees, Callery pear’s small fruit (8.5mm on average) is relished by birds, especially since they often have a tendency to hang on the tree well into winter- providing some much needed winter food for the birds that stick around.

Ok, so lets briefly put this all together: Ornamental= small fruit= bird food= birds poop= up comes Callery pear= produces thorns so not browsed= very tolerant of all the diseases= very tolerant of any soil type= it grows and thrives. But also, the Southeast is seriously just like China’s native range for Callery Pear (dark grey)…

https://www.researchgate.net/publication/232682928_The_Beginning_of_a_New_Invasive_Plant_A_History_of_the_Ornamental_Callery_Pear_in_the_United_States
https://www.researchgate.net/publication/232682928_The_Beginning_of_a_New_Invasive_Plant_A_History_of_the_Ornamental_Callery_Pear_in_the_United_States

I have two trains of thought that I’d like to go down: Fruit size and human impact on the land

1.) Fruit size: The average untamed fenceline in my climate contains autumn olive, barberry, multiflora rose, Callery pear, oriental bittersweet, honeysuckle, greenbriar, flowering dogwood, privet, american holly, hackberry, black cherry and a growing number of ailanthus. With exception to Ailanthus (which has a winged seed), what do all of these species have in common? They all produce fruits less than 15mm in size. Whenever there is a perch, such as a fenceline or a powerline, you’ll often see these species because they have small fruits that birds eat. The reason why we see so many Callery pear along these areas as well as in old fields and the built environment leads me towards the second thought…

2.) Human impact on land. Unlike many of the other species I mentioned in the paragraph above, Callery pear can thrive in compacted, low nutrient, poor draining soil with blazing sun and oppressive humidity. The reason why we see so much of it is because it thrives where humans have arrived and destroyed. Places like old fields, for example, which are are nutrient poor and compacted due to the robber-farmer that took more than the field could supply. Often in my area, those fields once supported tobacco and now are hayed by good-ole boy farmers in the area to keep the property in ag taxation for the owner, but no one ever puts any love/nutrition back into the land. What will grow in this scenario? Callery.

How can we make these pears less invasive?

Trying to conquer the Callery pear using agri-chemicals is dumb and only playing into industry-wide fear mongering in order to get us to buy their products. Birds gonna be birds, y’all, and though we’re doing a spectacular job at killing birds, there isn’t much we can do to stop them from eating Callery pears and pooping in marginalized areas. To think we can kill enough Callery pear to make a difference is a lesson in futility. So, with that said, here are my top ways to make Callery pear less invasive:

1.) Breeding. What makes Callery pear invasive is its ability to produce copious amounts of small fruits. 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. I have some ideas of how to do this in a controlled way (which I won’t go into on this essay), but this is happening in the wild already. Throughout the South and Southern New England, I’ve noticed trees that strongly look to be be hybrids of P. calleryana with P. communis (French) and/or P. pyrifolia (Asian). These trees have much larger fruits, often golfball sized or larger and are often loaded with fruits dripping from the trees. Little (or no) research has been done to evaluate the genetics of these larger fruited callery-like pears to see what exactly they are hybridized with, but if ever someone acquired funding to test the DNA, I’ll heartedly help supply specimens for evaluation.

But 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 Asian pears are likely your best bet for this, but this is also a random list I found online:

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Next, you’re gonna need to go into your pear thicket and do some cutting and grafting. I would recommend getting a forestry mulcher in and cut/mulch rows into the existing Callery stand. Then, get a group together to cut out trees within the row you left standing so the remaining are at 15 foot spacings. Then top the trees you’ve left behind and graft on the early blooming large fruited cultivars. In 2 years, your top-worked pears will be flowering and that’s all part of your plan, as bees will mingle between surrounding Callery and the large-fruited cultivars you grafted. All of a sudden, your chances of getting larger fruit to come up from that fertilized seed will exponentially increase.

I’ve been doing this bit by bit with with my business partners along the farm fenceline and after seeing how 2018 and 2019 topworked pears will be producing fruit this year, we decided to go big and do the whole fenceline. This year I’m grafting 40 or so cultivars onto the fence for evaluation and to hold them for a bit in a makeshift repository.

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One of the main reasons why Callery didn’t catch on as a rootstock, aside from propagation and hardiness, is that they weren’t dessert fruit. 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, 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 the Southeast. We need more people working with them in order to make this happen because they aren’t apples and they need their own methods.

2.) Use them as rootstocks! Every Callery pear growing is automatically the best rootstock around. For all of you people out there who are inundated with deer pressure, graft to the Callery pears above the deer browse. Sure, you’ll get lots of leafy re-growth off the trunk for a few years, but guess what- it’s really easy to remove with pruners and new shoots don’t have thorns. You’ll start to get fruit in 2-3 years.

I honestly think that Callery pears are the beginning the South needs to produce award winning, truly sustainable alcohols and fruit products. Southern wine that is drinkable is almost entirely made from grapes that are doused with chemicals (though there are some promising hybrids). Apples are the same way, unfortunately, outside of a handful of amazing grower/fermenters. Pears, though. Hybrid Callery or simply larger fruited Callery have a lot to offer, we only need to get over the absurd emotional press and embrace them (figuratively, as they often have thorns).

*The little girl in the photo is the author, circa 1986, for use as Callery clickbait*

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!*

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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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?