As a Landscape Architect, one of the most common concerns I encounter is that lawns do not grow well under trees. So I’m often asked how to make lawns grow there.Invariably, my response is “don’t even try!” Making north Texas lawns grow well within the root zones of trees usually means putting a whole lot of stress on trees, which often results in the tree's premature death (a tree under stress attracts more bugs, too, which can affect other plants as well). Lawns and trees are simply not compatible.
REASON #1A typical lawn requires a lot of water. A typical tree doesn’t. So if you water the lawn whenever it needs it, the tree’s roots will suffer – and may rot. Also, since it’s shady under a tree, the water will stay there too long - it won’t evaporate as quickly as it does in the sun.
Typical lawns require a lot of fertilizer. Since a high level of fertilization isn’t needed by most trees, they could “overdose” on chemical fertilizer. Some kinds will even kill them over the years. Even more damaging is the use of “weed and feed” fertilizer, or other chemical fertilizers with a high salt content, which can easily weaken or kill a tree.
REASON #3Since almost all lawns require sun, and a tree creates shade, a homeowner’s impulse is to remove some of the tree’s leafy branches. But a tree needs every leaf it creates, to grow. If too many branches are removed, the tree’s ability to photosynthesize is lessened, and it suffers.
REASON #4Disturbing a tree’s roots (even slightly) by tilling, adding soil or adding sod stresses the tree by interfering with its ability to obtain nutrients from the soil through its roots. This is why planting lots of cute little flowers beneath trees is a terrible idea.
Over the years, I’ve found that by far the most successful solution is to plant a ground cover under the drip zone of the tree. Forget about a lawn right there! The goal is to grow a ground cover in as much of the tree's root zone as possible. Of course, if the tree is a newly-planted “stick”, plan the ground cover bed for the tree’s size in about 10 years.
Some of the most reliable “under-tree” ground covers for north