Geneva Rootstock Bark

This is Cornell station in Ithaca. They field test new roitstocks all the time for five years and assess the outcome. They want to put out the best. They are not always right. Their condition may be different from yours.


They cut down this area where full size apples stood. they will put in Tall Spindle system.

The tall spindle is no more than 3 ft apart.


The experimental rootstocks Geneva is putting out need trialing by some of the ‘average Joe’s’ in a variety of settings. But, I think most would have a trouble if they had broken dormancy and had leaves…as my potted trees on M111 did.

I have read about lots of problems with several of the Geneva rootstocks . The NC140 rootstock trials tested many of the Geneva rootstocks in many locations through the country.

The recommendation for my area is G935. Unfortunately its susceptible to certain latent virus problems and most nurseries only sell it or custom bud it to certain varieties of certified virus free wood.

I don’t have any G935 but I have 50 G41 and 75 G11 which are doing very well. After just 2 years they are as big as many of my varieties on B9 after 5 years. I have not had any problems so far, but 2 years is not much time. I tried to prevent the trees from fruiting this year, so next year will be my first chance to evaluate the fruit from these trees. Hope its good because it’s too late to make a change.

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You are so right. I planted B9/Golden Russet and G 41 Rising Sun Fuji in the spring of 2016.

Hopefully, the pic is not too dark to see. Just took it this evening.

B9 is on the left. G 41 is on the right, stronger growth. I let both set fruit but only one Golden Russet has survived (so far). Fuji caries 7-8 fruit. Hopefully I can try the fruit of both varieties this year.


Perfect picture! It really demonstrates the difference. In my warm climate the B9 are especially small trees. Wish I did not have about 700 of them!


The things we find out AFTER we have them in the ground for a number of years.


We’ve had the same issues with our G41 grafts here in the wet Southeast. How have your trees fared since you shared these pics?


I’ve seen the shedding of bark on some of my Geneva trees. Good to know it’s not a serious issue.

My biggest problem right now is that three trees (one apple, pear and peach) have suffered significant buck rub damage this winter. I had removed the cages off of them because I thought they were being restricted in their growth and thought they were big enough to survive any deer munching on branches. Now I have to put cages next on the side of the trees where the damage is.

I’ve got a hunch that deer are making a comeback after being culled by disease a few years .

Somebody either needs to spread a Coronavirus that affects deer…or start eating some of them!

My four G series rootstocks have all cracked and split like that. It seemed to happen after we had a drought. We had a huge rain and after that is when I noticed all four rootstocks had split like that. I probably will not try any more Geneva rootstocks simply because of this issue plus the trees seem runt with their growth.

Allow me to refer you to the experts. Virus damage is still a theory.

Personally I am on the side of the mooooost recent actual research; viruses are a product of dead cells, not a cause of any disease.

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An update as to how the G series have done since splitting. All of them have stunted growth except one that is a decent size. Two of the tree that are stunted look scraggly and pitiful looking. The third of the stunted growth ones looks " okay" as far as filling out but still looks like it needs to fill out more. One looking good out of four is not a good ratio of trees on the G series rootstock.

Well, this thread was a fun find after I just bought mostly Geneva rootstocks hearing all the great buzz about them and their disease resistance :upside_down_face:

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After learning that M9 M26 and M29 are GMO I will be avoiding M series like the plague untill checking out all others… it looks like M111 is not GMO I like that rootstock, it better not be, and it was even in my mouth! PS M111 is good in wet clay soils.

Ill kick in my 2 cents, though it might not be worth that much. I have over 200 trees on Geneva rootstocks, most on G890 and G969, but also a fair number on G41. I also have trees on Bud 9 and M26. I have seen some weird results at the graft unions on all my trees, to varying degrees. Some trees have larger healing marks, others have bark that has flaked off, and others have colorations that are different from the rootstocks and the grafted varieties.
I have yet to have a tree die from an issue that i can definitely say was caused by the rootstock. Ive had whole varieties due out, in the case of Cox Orange Pippin. I had 7 trees, some on bud 9, some on G41, all died after about 3 years of slow, pathetic growth. Not sure what the issue was, but i wont be putting anymore COP in. I can say however, that some rootstocks that are vigorous growers can overgrow during periods of optimal ground moisture. This may be the case with the original post. When the actively growing cambium layer expands quickly, the outer bark is the weakest point and therefore splits, much like fruit cracking after a large rainfall event.


Based on the research publication it doesn’t look like all M9 M26 and M29 rootstocks are GMO.
Researches just used rolB gene-modified M9 M26 and M29 rootstock clones as a part of their research and compared results with a standard M9 M26 and M29 rootstocks.


  1. Rootstocks used in the trial consisted of non-transgenic M26, transgenic
    M26-rolB (clone F), non-transgenic M9, transgenic M9-rolB1 (clone ARB3) and M9-rolB2 (clone
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I think you’re right actually, but how can we know how to avoid the GMO ones? And what happens when they escape into the wild like GMO grass in Texas?

All of the commercial apple rootstocks are non-GMO. The Malling (M26,M7, etc.) series of rootstocks are very old and predate the GMO technology. The Geneva (G series) and Budagovsky (B series) are non-GMO as well.

Even if there were GMO rootstocks the risk of escape into wild is low. Now if the scions were GMO you would have much higher risk since the top part of the tree produces pollen and seed.

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