What would be the best kind of grass to grow in an area that is partial shade?
Your question is very timely because I just spent a few days at a grass research farm in Oregon and this very topic came up in a discussion.
In order to answer your question I think it is important to first understand the problem. In shady areas low light, poor air circulation and competition for water and nutrients combine to create an environment that is inhospitable to grass. Grass needs at least 4 hours of sunlight to produce enough energy for healthy growth and to defend itself against disease. If the area in question has less than 4 hours of sunlight I suggest planting a shade tolerant ground cover or consulting a tree trimming expert about removing a few limbs to allow more light into the space. If you have high shade, dapple shade or partial shade with more than 4 hours of light, you can grow grass. It won’t be as thick as a lawn in full sun, but based on the test lawns I saw at the grass farm it can be quite lovely.
A research technician at the grass farm gave me a few tips on how to grow a beautiful green lawn in shady areas.
While grass does best with plenty of sunlight, some types have proven to be more shade tolerant than others. Here are some choices based on the region of the country where you live. Cool season grasses are typically grown in northern areas of the country, started from seed in either spring or early fall. Many southern gardeners can also sow cool season grasses in the fall for a green lawn from winter through late spring. Cool season grasses that do well in shade include fine fescue, turf type tall fescue, and perennial rye. Look for blends of cool season grass seeds designed specifically for shade. Warm season grasses are grown primarily in the south. They are grown in summer and go dormant in winter. The best warm season grass for shade is St. Augustine, but some varieties of zoysia such as ‘Cavalier’ will tolerate light shade. Warm season grasses should be planted in mid-spring to early summer.
Turf grasses grown in shade need about half the nitrogen as those grown in full sun. Apply the fertilizer at 1 pound per 1,000 ft2 in late spring after the grass has begun to green up. In the early fall feed again. If you are establishing a new lawn use a starter fertilizer. A soil test is recommended to help you determine the best starter blend for your situation.
When mowing the grass in shady areas, raise your mower blade so that it cuts the grass to about 3 inches tall. The extra grass length increases the amount of leaf tissue available for photosynthesis, the process that produces energy for the plant. But don’t allow the grass to become overgrown and scraggly. Removing more than 1/3 of the plant at a time will cause root shock. This slows root development and weakens the grass.
Grass is competing with neighboring trees and shrubs for moisture so you want to provide adequate water without over watering and promoting fungus. Water deeply to prevent shallow root development and then give the area some time to dry out between waterings.