People like lawns. Kids enjoy expansive green areas where they can play. Lawns can improve the curb appeal of homes. However, some homes are very shady making growing lawns more difficult.
Grasses are generally FULL SUN plants. Grasses need at least 6 hours of full sun to be healthy. You do not find grasses growing in the shade of trees in nature very often. Sod farms are in full sun locations to maximize grass growth and health. Grass lawns can be grown in the shade of trees but will need extra inputs of water, fertilizer, annual over-seeding and sometimes pesticides to remain healthy.
This non-irrigated fescue lawn is turning brown in the shade of the trees where tree roots are using up the limited soil water. This lawn needs to be irrigated and fertilized to overcome the competition with the trees.
PLANTS NEED THREE THINGS TO GROW: SUNLIGHT, WATER AND NUTRIENTS. Where people do try to grow grass in the shade of trees, the trees can outcompete grasses for sunlight, water and nutrients. Trees will get plenty of sun while grass gets very little. Plants use sunlight to create food utilizing photosynthesis. This means grasses grown in shade may be less healthy and more prone to disease. Tree roots and grass roots occupy the same soil and compete for nutrients and water. Shady lawns will slowly become thinner as grass plants eventually die out if lawns are not supplemented with nutrients and water and overseeded annually.
Conversely, grass lawns can negatively affect trees. Grasses may outcompete trees for limited soil resources. Herbicides used on grasses to control broadleaf weeds may affect tree health negatively. Lawn mowers are heavy and can compact soils and damage tree roots. String weed trimmers can damage tree trunks if used improperly. Studies have shown that trees are healthier when the critical root zone is mulched with 2-3 inches of mulch out to the dripline of the tree canopy.
Properly maintained fescue grass makes a beautiful and inviting lawn. Grass grown in full sun performs better and makes for a healthier lawn.
Grass can be successfully grown in shade but it requires a little extra work. Simply seeding or sodding once without after care will not work in many cases. If you do have grass growing in the shade of trees, there are a few things you can do improve the stand of grass:
hire an arborist to trim trees to allow more light to get to the grass
perform a soil test to determine how much lime is needed to adjust the pH and what fertilizer would best
utilize shade tolerant fescues which can survive under four hours of sunlight
aerate and overseed shady lawns each fall in September to fill in areas that have thinned due to shade; Weeds and mosses can invade thinning grass stands
irrigate shady lawns during periods of drought using the equivalent of one inch of water per week
fertilize shady lawns in the fall and spring
mow shady lawns infrequently and leave the grass as tall as possible
avoid foot traffic in shady lawns
If you have given up on your shady lawn, there are alternatives.
