Grass in the Shade
Growing grass in the shade is a major challenge for many homeowners because an estimated 20 to 25 percent of all grassy areas are shaded to varying degrees.
It's not always advisable to try to maintain dense grass in all shaded conditions because even the most shade tolerant grass needs at least 50 percent sunlight or a minimum of four hours of sunlight daily to survive. But the following suggestions can maximize grass growing in shady areas.
Begin by selecting the most shade tolerant grass species possible for your climate. Not all grass species are created equal, especially when it comes to light requirements. Independent researchers have concluded the following rankings for shade tolerance.
For warm season grass, recommendations are (starting with the most shade tolerant):
- St. Augustinegrass
For cool-season grass (starting with the most shade tolerant):
- Fine fescue
- Kentucky bluegrass (shade tolerant cultivars)
- Tall fescue
- Perennial ryegrass
- Kentucky bluegrass (non-shade tolerant cultivars)
It is recommended that you consult with someone at a top-quality nursery or garden center, a university turfgrass extension specialist, or a professional sod producer in your area for their specific recommendations.
Once you have chosen a grass, it is recommended that you select trees that complement it. Trees with dense canopies and/or shallow root systems create problems for grass because grass will be forced to compete with those trees for water and nutrients. Avoid maples, oaks, magnolias, elms and sweet gums because of their dense canopies. Steer away from beeches, maples and willows because of their shallow root systems.
The open canopies of trees such as poplars, birches, pines, locusts and ginkgos can match well with grass.
Pruning a tree's canopy and its lower 8 to 10 feet (92.5 – 3 m) of limbs will allow more sunlight to reach the ground, but it may be destructive to the tree or spoil its natural appearance. If you can't achieve minimal sunlight for grass, switch to a more shade tolerant ground cover.
Adjust turf maintenance practices to maximize the chances of success.
- Water infrequently, early in the morning, applying enough water at a single time to moisten the soil five to eight inches (12.5 to 20 cm) deep. This approach will reduce the potential outbreak of turf diseases that thrive in damp, shady areas.
- Mow at the maximum height range recommended for the grass species, using a sharp mower blade, and removing no more than the top one-third of the grass blades in a single mowing. Most heavily shaded grass grows upright and stringy to increase the leaf surface and capture any available sunlight. Mowing at maximum recommended encourages this.
- Fertilize at half-rates of nitrogen, as compared to the sunnier areas of the lawn, and increase potassium rates. Nitrogen encourages succulence that can decrease wear tolerance and increase disease susceptibility. Potassium can improve wear tolerance and decrease disease susceptibility.
- Herbicide applications should be used rarely because this will place another stress on an imperfect growing situation.
- Reduce heavy foot traffic in shaded grass areas. As fragile as shaded grass plants are, it doesn’t take much to tear out their shallow root systems, or damage the plant beyond its ability to recover.
Another suggestion is to re-sod heavily shaded areas every few years, as part of the yard's overall maintenance and improvement plan. Stripping off the nearly non-existent grass and replacing it with dense, mature sod can immediately refresh a shady area. Knowing that even the most shade tolerant grass will thin over two to five years and planning to re-sod at that time can accomplish a homeowner's dream.