Root suckers
Also called: suckers, suckering, root sprouts, stump sprouts, tree growing back from roots, regrowth after stump grinding
Shoots that sprout from a tree's surviving roots after the trunk is cut or the stump is ground — the way poplar, aspen, elm, black locust, tree of heaven, willow, sumac and crape myrtle try to regrow. Grinding does not stop them; treating the fresh stump or cutting the shoots repeatedly does.
Most trees die when the trunk is cut: the roots have no leaves to feed them and exhaust their reserves within a season. A minority are built to survive exactly that — clonal species whose roots carry dormant buds and respond to the loss of the trunk by throwing up shoots, sometimes dozens, across the whole root zone. Aspen and poplar are the classic case (a single aspen clone can be acres), and elm, black locust, tree of heaven, willow, sumac, crape myrtle, some plums and cherries, and lilacs do the same on a smaller scale. A ground stump makes no difference, because the buds are on the roots the grinder never touched.
The options, in order of effectiveness. Before the tree comes down or right after, paint the fresh cut surface of the stump — the outer ring, where the living tissue is — with a concentrated herbicide labeled for cut-stump treatment; the roots draw it down and the suckering mostly stops. It has to be done within minutes to an hour of the cut, before the surface seals, and before grinding removes the surface. Otherwise, cut or mow every sucker as it appears, all season, for one to three years; each shoot the roots produce and lose spends reserves they can’t replace, and they give up. Pulling suckers, which tears the root, works faster than cutting. Digging out the roots is the nuclear option and rarely worth it.
If a tree that’s coming down is on the list, tell the crew — the hiring guide has it on the checklist — and decide about treatment before the saw starts. The cost page counts the suckers among the hidden costs for a reason.