Planting Under Trees

Spring is the time for trying new things. And since grass does not grow well under most trees, some gardeners wonder if they can replace their struggling grass. The answer is yes, but be careful.

Like grass, any plant will have a difficult time trying to survive beneath a tree. One of the biggest reasons is those plants have to compete with the tree’s extensive root system for nutrients and water.

Many plants will do just fine in that tough environment, as long as they get some extra water and fertilizer. But when planting, be careful not to damage the tree’s roots. A lot of people think tree roots are deep in the ground, but the reality is that 90 percent of a tree’s roots are located in the top 3 feet of soil under and around the canopy.

Shade-loving annuals like impatiens might add color under a shade tree, but if you plant them you have to disturb roots every year. That’s why it’s better to go with perennials under trees if you can, and just tuck in a few annuals for color.

If you have to remove grass, hand dig as carefully as you can. Try not to cut through roots larger than 2 inches thick as those are more vital than smaller roots. Use a garden hose to determine the shape of your bed rather than going with a standard circle, which looks less natural. And choose plants that can tolerate the dry, shady conditions of an understory, such as barrenwort, bleeding heart, ferns, and Solomon’s seal.