Hello everyone! This is a tree that was grafted to M111 rootstock back in 2020, the union is right by the green cable in the top of the image. I have a handful of trees like this with 6+ inches of rootstock above soil level and the burr knots are pretty intense. I now set my grafts lower on the rootstock to avoid having too much above soil level, but I would like to learn more about what direction I should take these burr knot laden trees.
Is it safe/would it be helpful to plant these as deep as possible without burying the scion? Should I expect to cut out suckers for the rest of the trees life if doing so? Any input is welcome.
I had four trees I got from a nursery that did that. One of them had the bark die on one side. I finally put it out of it’s misery this winter (it kept getting knocked over, kinda surprised it was still alive and attached).
The others haven’t grown much.
What I should have done was bury them deeper at planting and accept the risk for increased suckering, but I didn’t know that at the time. If you bury them with dirt now, you will suffocate the roots I think and might cause trunk rots.
I think there is a way to cut out the burr knots. I am not familiar with this.
i have planted young MM111 really deep. And those where fine.
I’m not sure how an older stem would handle being buried deep though. But since bur knots can form roots. even if the roots your burying deeper don’t make it, it will like make loads of new replacements. Maybe water them extra the season after replanting.
I have no practical experience with this. But i think in theory you could use inarch grafting
Taking a long scion of the variety that’s grafted on the MM111 and grafting that from roughly 2-4 inches above ground to slightly above the graft union. (bypassing a long piece of the MM111 main stem)
Once this inarch graft has taken. You could notch or make small cuts or tie off the MM111 part, to force the tree to thicken up the inarch part. I would support the tree with a post for a few years though.
Im not sure if it would be worth the hassle/risk.
Bur knots are not ideal. But you can usually live with them fine.
If you are confident it is m111, you could temporarily put a mound of something (sawdust, woodchips, something easily removed) around it and let it make suckers. Then you could clip those to make new rootstock and re-graft the variety you want.
Or, bury this rootstock deeper and hope for the best…
Yes mm111 will always do this if left out of the ground. A mound of dirt covering up to the union would be fine. Dont cover the union because the scion will also root.
I forgot to mention that this tree is still in a nursery row, so judging by your advice it should be safe to just plant it deep enough so that the union is just above soil level?
I know planting an oak too deeply, or mounding up soil, so that the root flare is covered can be deadly. It’s interesting that this may not be as much of a consideration for apple trees, at least in certain circumstances.
M111 rootstocks produce suckers and burr knots. The latter does stunt the tree, at least in my yard. I follow the advice from @applenut and bury the rootstock right up to the graft union. If I remember correctly, the exact advice in his videos was to leave two finger distance for the graft above the soil level.
Having said that, M111 rootstocks have the right amount of vigor for our climate and water we can afford to irrigate hence the preferred rootstock here.
Good advice. I have mostly M111’s and a few of mine have the burr knots but not all of them. I have a few more M111’s coming this year so I will bury them deeper than I had done before like your suggestion here.
In reading this article shared by you @clarkinks, the author actually says they don’t recommend planting m111 deeply because of the risk of crown rot. I’m sure this isn’t an issue if you’re dealing with newly grafted trees, but with these trees going into 4th leaf it leaves me wanting to further investigate this.
@alan do you have any input on this topic? Through searching the forum I’ve read about your fruiting-age nursery and that you like working with m111. I’m on Long Island, so I’m also curious about your take on this because we are relatively close to each other.
You don’t want to bury any trees below the graft union, but I fail to see how planting at the union is going to contribute to crown rot and 111 is more resistant to it than other rootstocks to begin with, so I’m guessing they must be talking about burying the scion.
In my climate 111 has never has had any issues because of burr knots or crown rot, and I manage it in scores of sites with different levels of drainage- although I find ways to improve drainage when there’s a problem.
If I wrap plastic around the trunks including below the graft union, wooly apple aphids will exploit the conditions but they’ve never become a truly damaging issue in the environments where I grow trees, but Long Island is different and I’ve only managed a couple of orchards next to the beach. It is like another country if you have full coastal influence with a slew of issues due to the almost constant high humidity.
I would spray the daylights out of the burrs (cuprofix for fireblight along with dormant oil.). Great entry point for all kinds of insects (especially borers) and even fireblight. Problem is you cannot use Pilot/Lorsban (Chlorpyrifos) anymore which was the best choice against the borers. Call the extension service and find out what they recommend instead for the bugs in your area. In my entire orchard, including many M111’s, I have only one tree with burr issues (a Winecrisp and this is much higher up). Usually, I dig an 18" or deeper hole - a real bear in our clay (fill underneath as necessary) (20" circumference) and make sure the union clears the dirt by 3-4 inches. Also, I have not planted M111s in several years. I am almost exclusively a G-890 P220 guy now. My friends with really big orchards (300 acres plus - 90K trees) do not use M111 - they use M26 or even full sized types (M-9 for self-picking and even M9 on trellises).
Most of my MM111 formed burr knots in the first year in Northern Florida. What I found is that if you leave them too long, then they rot out while at the same time protruding and preventing the cambium to cover the area. So, I think that the best approach is probably to burry low burr knots on the root stock while the burr knots are still alive, or if you got a decaying burr knot, cut it out and leave the area exposed to air to heal.
hence the preferred rootstock here.