Usually rocky soil is found near or on top of high mountain ranges such as the Adirondacks or the Rockies. Mountains and foothills are supported by rock formations that run under the soil; since rocks weather over the years, there will often be a layer of soil above the rock in which grass can be planted. Planting grass in rocky soil can be challenging, but it is not impossible. With proper preparation of soil, creativity and willingness to experiment with different grass cultivars, you can create a thriving and ecologically beneficial yard.
Fringe Benefits of Rocky Soil
Take advantage of the fact that herbs such as oregano, parsley and sage thrive in rocky soil, and use them as accent pieces, borders and edging. Large, visually interesting rocks that have been pulled from the ground can be displayed as decorative features, and pebbles that have been removed from soil can be used to help drainage in planting beds.
Rocky Soil Preparation
The best way to prepare rocky soil for planting is to use a tractor to drag subsurface rocks across the planting surface and to the side; in areas where that is not possible, a tiller may be used. Make sure it is sturdy enough to accomplish the task of moving the rocks without being damaged. If the soil is extremely shallow, you may need to use planting beds. Till the soil to two inches; if you don't have two inches of soil, you will need to add topsoil. Rake level, roll the soil to firm up the bed and seed generously.
In order to succeed growing grass in rocky soil, you must choose cultivars that will work with your particular terrain and soil. According to gardening expert Ellen Brown on the Thrifty Fun website, the best seed mix for rocky soil is one made up of grasses that are native to the area. The grasses will establish themselves more easily and also be more resistant than non-native varieties to damage from diseases, pests and drought. For a yard that is natural, beautiful and easy to maintain, consider establishing a prairie meadow on your rocky soil, with wildflowers blooming against a backdrop of native grass. Use self-sowing grass, such as blue grama grass; butterfly weed, black-eyed Susans, wild bergamot, and nodding onion are all good choices for wildflowers. Other hardy and attractive plants, such as asters and goldenrods, will establish themselves naturally. Plant tree seedlings, such as a few hardy pines or oaks, in order to promote diversity by creating shaded areas. Plant the young trees in fall or very early spring to ensure their survival, and keep them well watered. If you have your heart set on a more conventional lawn, however, you could try sowing buffalo grass, a native grass found throughout the Great Plains from Minnesota to Montana and down into Mexico. Buffalo grass, which tolerates rocky soil, spreads by means of runners, or stolons, and is resistant to drought, severe winters, pests and diseases. Another option is to plant tall fescue grass, a medium-coarse-textured cultivar that tolerates poor soil quality. Once it has been established, tall fescue has good resistance to drought and also can survive harsh winter weather. You might also consider trying bermuda grass, which can grow with minimum topsoil base.
Tips and Precautions
Planting some rye grass along with the perennial grass you have chosen will provide a quick cover and help to protect the perennial seed. Consult with native plant nurseries about the best grass varieties for your area; you can also visit the US Department of Fish and Wildlife website. To avoid injury, wear eye goggles and use caution when using a tiller to remove rocks; they may bounce up from the ground.