Lawns under the shade of trees are typically thin, weak, and of poor quality. Maintaining a quality stand of grass under the shade of trees can be difficult and requires modifications in lawn care practices. Shade-tolerant grasses still need an acceptable amount of light to grow. In addition, lawns in shade areas generally do not have the ability to tolerate or recover from stress problems as compared to lawns growing in full sun.
Choosing a shade-tolerant grass mixture is critical. Red fescue or other fine fescues are the primary lawn species in these mixtures. See Lawn Grasses for Northern Illinois.
Start improving shade areas for grass growth by pruning vegetation (trees and large shrubs) as much as feasible to allow the maximum amount of light to reach the soil surface.
Care of established lawns in shade areas will be different than lawns located in full sun. Mow higher (near 3 inches), and fertilize less in the shade, as too much nitrogen can be detrimental to shade lawn species. About one to two pounds of actual nitrogen per 1,000 square feet per growing season is all that is needed. When watering shade lawns, do so as infrequently as possible, and water deeply. Reduce traffic over lawns in the shade.
If these practices have been followed but the lawn still fails, there probably is not enough light even for a shade-tolerant grass species. Often a shade lawn mix is seeded, comes up fine, but declines rapidly due to a lack of sufficient light. If lawn grasses have failed, try a shade-tolerant groundcover (refer to Groundcovers as Lawn Alternatives for Shade); or mulch, possibly in combination with ferns or woodland plants.
Lawns in shade often have problems with moss or shade-loving weeds. Ground ivy (creeping charlie) or nimblewill are prime examples of shade-tolerant weeds. These problems exist primarily because the lawn grasses are thin and weak, allowing easy invasion. Follow the steps outlined above to help avoid these problems. Refer to other topics in this series for specific control options.