If your garden grass is patchy, consider a ground cover instead via chicagotribune.com

Homeowners often are frustrated when the lawn looks bad beneath trees. Starved for sun, the grass is thin and patchy.
The problem is that most popular lawn grasses are full-sun plants, according to Doris Taylor, Plant Clinic manager at The Morton Arboretum in Lisle. Even grass species sold as “shade-tolerant” will struggle in deep shade.

You also may choose a ground cover to replace lawn in any shady area where there isn’t enough sun for grass to thrive. Use a ground cover on a slope where mowing grass would be inconvenient or even dangerous. It can be the best option for a small city front yard or a courtyard.

What is a ground cover? “It’s not really a particular kind of plant,” Taylor said. “It’s any perennial plant that can be used instead of turf.”