“Can you please send someone out to look at our Sweetgum? It just dropped a big limb on our deck. Someone could have been hurt! What I don’t understand is that it was perfectly calm – no wind at all – and there are green leaves on the branch. What’s going on?”
We’ve had numerous calls like this one this summer. For some reason a branch will just drop off a perfectly healthy deciduous tree. It doesn’t necessarily mean that the whole tree is about to fail, or even that other branches may fall. The calls usually come in the summer, and although this summer has seen more calls than usual, we get similar calls every summer. Arborists call this sudden branch drop, or sudden limb failure, and other similar descriptions.
There are several technical explanations about why this occurs; however, there is not a consensus about any one reason. Arborists don’t really know!
What we do know is that this can happen to most deciduous trees. Especially prone are Sweetgums and Yellow-Poplars. When it happens, you should have the tree visually assessed by an Arborist to determine if there is anything else going on. For instance, cankers, decayed branches, dead/dying branches, insect infestations, fungal infections. It would be best to examine the tree while the branch is still there to see if there is decay present in the branch. The Arborist will recommend what to do about anything observed. In the likely event that it is Sudden Branch Drop, it is usually possible to keep the tree, but with some possible adjustments.
The recommendations are commonsensical. For instance, don’t locate a summertime people activity center below a Sweetgum or Poplar. If there are large branches extending over your roof, deck, etc., consider trimming them back. If a significant portion of the tree is over something valuable, consider removing the tree. And always, keep these and other trees healthy with mulching and regular watering.