Hello Gardeners, I’m Amanda McNulty with Clemson Extension and Making It Grow . Mulching trees is the best thing you can after you’ve planted them properly; some research shows it can double the rate of growth for newly established trees. A good tip when mulching trees is to think of doughnuts – there’s a hole in the middle. Mulch should start from four to six inches away from the tree’s trunk, if it touches the trunk it promotes disease and decay. Let the mulch extend out at least three feet,