Apple Rootstocks & Tree Size

In her book on growing small fruit trees, Ann Ralph posits that dwarfing potential is the least important thing about a rootstock, that the best way to control size is with regular pruning, and that a dwarfed root system may compromise the health and longevity of the tree (including raising the risk of the tree toppling over). On the other hand, more-local-to-me orchardists have recommended dwarfing rootstocks (particularly Bud9 due to less susceptibility to fire blight).
I’d be grateful to hear the view of experienced fruit growers that are in or near northern Maryland. I’m a neophyte and the conflicting advice on rootstocks is challenging. Could someone throw out some advice for apple rootstocks in northern Maryland when the goal is to keep the trees relatively short? Thanks much!

To me one benefit of dwarfing rootstock is that it bears fruit earlier. That is a very important factor.

The toppling issue can be easily addressed with supports

Mike

MES111, What rootstock do you like for apples and why? Thanks again!

The way that I understand how dwarfing happens is thru incompatibility. Its by its nature a hobbling of the scion. Whether thats a good or bad thing depends your natural environment. In the central valley of California (basically stone fruit heaven) I think that dwarfing root could be a big advantage for size and precocity. In more fringe environments that are somewhat unnatural to fruit trees, I believe it be a bad compromise leading to unhealthy trees and poor insect/disease resistance.

Here on our land on the outskirts of Phoenix apple dwarfing rootstock shows poor growth and extended summer dormancy. We have moved completely away from dwarfing rootstock to standards. And are managing size thru pruning and holding back irrigation at times after harvest. So the answer is that it really depends on the local conditions.

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I’ve heard nothing bud good about Bud9 rootstock. But I agree you can keep just about any tree the correct size if you prune it properly. Watch some of the Tom Spellman videos.

And who is Ann Ralph?

She may not be adequately fleshing out her point as it is partially true and partially false.

Some dwarfing rootstocks produce long lived trees and some don’t and some trees can be kept small and productive on non-dwarfing rootstocks in some parts of the country (where it doesn’t rain during the growing season) and not so much in others (the humid region).

In general, a more vigorous tree has better chance of long survival but if you leave it at that without further explanation you do a disservice to your readership.

Most dwarfing apple rootstocks can produce long lived trees and are extremely helpful in keeping a tree small and productive of high quality fruit. Yet the most dwarfing are more likely to be killed by voles or even deer than trees on more vigorous rootstocks.

The same can be said for the Geisela rootstocks for cherries and Citation for plum.

Those are examples I have enough experience with to speak of with some authority, as least as it applies to the northeast.

I believe dwarfing peach rootstocks probably fail everywhere for producing long lived trees. Maybe because peaches are not that long lived to begin with.

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Ann Ralph is the author of “Grow a Little Fruit Tree.” She is an experienced grower and teaches pruning classes, but she is in CA. I recognize that the climate there is vastly different from the northern part of central MD, where I am.
Your feedback was helpful, Alan. Thanks much.

Sorry to dredge up an old topic, but I’m working on the same problem. I read Ralph’s book and am (generally) on board with the principles involved, ie summer pruning to control vigor vs winter pruning for structure. I started off my horticultural adventure with training bonsai (which sadly succumbed to too many moves and poorly selected plant sitters). The techniques are basically the same, if less intensely applied, and I know they will work. However, I also know that you need to keep at it and it can be a lot of work! I’d been thinking of growing Harrison apples on Bud 118 and summer pruning to maintain 10 ft spacing. I’ve been reading that Harrison can be pretty vigorous and now I’m second guessing myself. I’m wondering if I’m better off with M26 or Bud 9 and putting up with staking for the first few years. Or should I trust my gut and be sure to keep the pruners handy?

How about M26/Bud9 as an interstim on seedling or M111 or similar rootstock? Unless there’s something I’m missing, you get a smaller tree that is more precocious, but a strong root system so no staking. Win-win?

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I have a few apples with Bud9 interstems/m111 roots. I still have them staked but I think eventually they wont need it. Very precocious.

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I have a G11/MM111 Rubinette interstem that’s compact and precocious but well-rooted and wind- and drought-resistant. Interstems can be a good option if you want that combination of characteristics.

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I hear that Harrison is a beast for rampant growth. Would be a great experiment to see if you can control it by beginning controlling work early on: branch bending, summer topping plus maybe early full cropping (unthinned?) to slow it down. Might throw it into biennial bearing but keep growth in check. No expertise here on Harrison but would love to see someone try this.

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I hadn’t thought about an interstem. I should consider it. My biggest concern (other than buying extra rootstocks) is that this will be my first year grafting. I’m reasonably confident that I can get something to take, and I know there’s always next year if it doesn’t work, but I’d rather not increase failure points.

That being said, if Harrison is as rampant as @hambone suggests, it may be helpful to have some built in throttling if I get off my pruning regimen.

I don’t doubt it’s possible to control it using cultural methods alone. My bonsai experience taught me that it’s not that hard to keep any tree healthy at any size from a few inches to as large as you can manage if you keep the vigor in check with multiple prunings a year. Bonsai also benefits from a very rigorous root pruning, but that’s at least as much about keeping it from getting root bound than controlling vigor. Summer pruning of an in ground tree would have much the same effect. I might be screwed if I miss my summer timing, though…

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I have several trees that I grafted as interstems and I think it has promise, but just like rootstocks themselves, the choice you make matters immensely. They aren’t a silver bullet, at least in my experience. I wanted small trees so several of my more vigorous types I grafted onto M111/M27 and the less vigorous I grafted onto M111/Bud9. I expected the M111/M27 to equal approximately Bud9 in vigor, but the end result is definitely less vigorous. It probably doesn’t help that the deer have done more “summer prunning” than I would have, so that has kept them smaller. The other thing is I find the M111 suckers a lot. I would guess it is more than normal, because it is basically throttled by the interstem so maybe it is pushing more suckers with the left over vigor. I’m actually planning to bridge graft some of the M111 suckers into the scion to circumvent the interstem this spring as an experiment to get more vigor back into the trees. You also have 2 graft unions per tree, so more that can go wrong over time. Some of my graft unions have gotten pretty lumpy and ugly over time, but still holding and growing.

I originally went with the interstems to have freestanding small trees that wouldn’t need careful watering due to weaker roots. When I wanted to add a few more trees, I went with G969 instead and just intend to keep them small through summer prunning. We’ll see how that works out, but so far I prefer the greater vigor I’m seeing. There are some people having various issues with some of the Geneva rootstocks, particularly with budding and some virus issues, but I whip and tongue graft and I think the G969 has been pretty good. I’d also consider G890.

In terms of grafting, I did the interstems as bench grafts, doing both the interstem and the scion at once (double graft) and had a high level of success. So I wouldn’t worry about that too much. Plus you can graft onto the remainder of the rootstock from whatever you use as an interstem and get a tree directly on that root at the same time as the interstem tree. I’m not against interstems, but I think predicting the actual vigor you’ll get isn’t as straightforward as I expected and there is the suckering and possible issues with having the added union (point of failure) over time. If I did interstems again I’d go M111/Bud9 for vigorous types and M111/Bud118 for the less vigorous. I know Bud118 is pretty close to M111 in vigor, but I think it is more precocious and I think M111 might be better in my clay soil. I like the tried and true nature of the M111 base and what I think is a very good track record for the Bud rootstocks as well. Long term, less is known about most of the Geneva rootstocks, especially some of the more recently released.

In the end, my experience tells me to consider soil, drainage, freestanding/staked, required disease resistance, etc. first and see if interstem offers enough possible advantages to be worth the effort/risk. And I’d always go with more vigorous than I thought I might need, either in the interstem combination or the straight rootstock, to give me more pruning options to shape the tree and the extra vigor I might need to overcome deer, drought, disease and other things that might come along. Because inevitably they do.

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In my experience, all apple rootstocks have been equally precocious. I’ve used Geneva 222, Bud 118, EMLA26, EMLA 27, Bud9, G41. And a few others I’ve forgotten. All of them bear in second or third season after grafting.

My inclination is to use more vigorous Bud 118 or Geneva 222 and keep them pruned for size.
My oldest trees (over 15 years old) are on EMLA 27 and I strongly regret getting them on that rootstock.

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What has been your experience with your old super dwarves?

My two interstems are probably my best trees but they both have mm111 on the bottom which is just great here. One is a bud 9 the other a g11 and both do really well (even though g11 is the only rootstock to ever die for me) the interstem performs great and keeps a nice small 6’-8’ tree.

I wonder what semi dwarf tree was the ones my family friend had. He bought them in like 1919 or 1920 in california to bring to colorado and went for hardy selections. They were all burred up but very old by the time i saw them and in good health. My thoughts is maybe mm111 they were very drought tolerant.

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MM.111 was introduced in 1952.

It was probably some variant of the Paradise rootstock (you can read here about history of apple rootstocks).

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I was going to contradict this and searched and searched for the specific release date thinking that Richard was correct. I finally had to go to my bookshelf because Google search was useless and found out the the release of the MM series was, in fact, 1952.

If I’d stuck to what I could find on Goolge I would have believed that Richard’s date was correct. Even the link you provided didn’t provide its release date or indicate that earlier work didn’t produce any of the popular English rootstocks used today, except EM7 and even that is a clone of the original produced in 1959 to free it of rubbery wood mosaic.

I found this in Tukey’s “Dwarfed Fruit Trees” which was first published in 1964 and probably last printed in '83. I purchased the book a quarter of a century ago.

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This is the 2nd link that google shows when I search for “MMM.111” rootstock: Apple Rootstock Info: MM.111 EMLA – Apples.
It says: “Introduced in 1952 from a cross of Merton 793 x ‘Northern Spy’ by the John Innes Horticultural Institute and the East Malling Research Station in England.”

Hatton started working in East Malling Research Station in 1914 and the link that I gave in my previous post says that John Innes Institute of Merton joined with the East Malling station to begin a breeding program in 1917. Even if they made the cross that produced the MMM.111 rootstock immediately in 1917, they would only be able to start experimenting with it as a rootstock in mid-1920s, and it takes dozens of years to learn all rootstock characteristics.

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Yeah these were really unique trees and I very much wonder what rootstock he used. He grew them at a 45 degree angle and kept them under 8’ in a dutch fence espalier style. There were no supports and he only supported trees right before harvest with crutch type devices. I only remember a few of his varieties for sure Grimes golden and golden delicious because they were on opposite corners of each other and “mother and daughter trees”. He said he grew american apples on semi dwarf rootstocks from europe and that he bought a majority of his non peach trees on a trip out to California after purchasing his property because he could not get what he wanted here. There were only 8 of them with each row having 4 and maybe 20ft to 25ft long. Each apple alternated green or yellow and red and all the red where striped apples and it was just magnificent.

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