Q: How effective are tree growth regulators for maple trees? I’ve got some twenty-five-foot high maple trees on a sloped hill. They’re doing well but I’m wondering if I can slow down their growth.

A: Chris Hastings (www.arbormedics.com) says he is not a fan of growth regulators. UGA tree expert Dr. Kim Coder talks about the hubris of arborists trying to control the complexity of nature by dumping hormones on a tree. Growth regulators are meant to divert top growth to root growth. This means the roots become supercharged and will eventually unleash their pent-up energy into the canopy. A better choice might be to schedule an arborist visit every couple of years to thin the trees. In the world of bonsai, miniature trees are beautifully kept in check by regular top pruning and root pruning.