IMUST HAVE SLEPT THROUGH A SEASON OR TWO, because it wasn’t until some big yellow crabapples formed right beside the little red ones a particular tree of mine is supposed to have that I thought, hmmm, I guess that’s rootstock making its way skyward. Oops.
Don’t be horribly alarmed; I didn’t fail to notice an entire branch emanating from the ground-level root zone. This is a high-grafted tree–a weeper made from combining roots and a trunk of one variety with the desired flowering and fruiting head of another–so the branch came from just below the union where top meets trunk, sneaky thing that it is.
I don’t have the heart to prune off the errant branch until some bird or another comes to enjoy those little golden gems, but then I promise: I will. I do know how to prune, I do. I just sometimes don’t know how to pay attention, apparently.
This may help you to feel better: I just discovered I had ignored 5 straight branches that grew up inside my contorted Harry Lauder! They have been terminated with extreme prejudice.
Might you consider leaving it? The combination of the two kinds of crabs on one tree is like a bouquet of crab apples. Or would the lower rootstock just overgrow the graft?
Like Linda, I’m wondering if you can just monitor the new growth and perhaps keep it under control so that you have two varieties of crabapples for the space of one? I have seen advertisements for trees that grow multiple varieties; do they need to be micro-managed in order to prevent the root stock variety from taking over the whole thing?
I think the problem with letting the rootstock grow in this situation is the upright growh habit, which would run contradictive to the weeping habit of the graft. That would look downright silly in the future. A botanical cowlick, so to speak.
I love these little accidents — I once had the most wonderful bridal wreath bush growing within a lilac. They bloomed at the same time and were glorious. Yellow and red crabapples together is just delightful.
I too love these little mishaps of nature, that ‘s how I have ended up with a wild rose bush climbing up a cherry tree!