How To Keep Roundup From Tree Roots

Q: I have a lot of old pines and dogwoods on my property. English ivy, trumpet vine and poison ivy are trying to take over everywhere. I would like to spray Roundup and kill everything but I’m concerned about getting it on the tree roots. 

A: The label on glyphosate products, like Roundup, directs users to avoid spraying on trunks and roots. In my observation, trees with thin bark, like American beech or crapemyrtle, are more likely to be hurt by the weed killer than trees with thick bark, like pine. If you are conscientious about spraying glyphosate only on the leaves of the underbrush you’re trying to control, I believe you can use it effectively without hurting the trees.