Grasses for Alkaline Soils

St. Augustine Grass

• A warm season perennial grass, St. Augustine grass (Stenotaphrum secundatum) tolerates a pH level of 5.0 to 8.5. Unfortunately, when the pH level rises to above 7.5, the grass does lose its deep, dark green coloration and appears slightly yellow. St. Augustine produces a satisfactory turf grass that tolerates moderate foot traffic. It grows best in full sunlight but will withstand partial shade. The grass prefers a humid environment and can withstand soil salinity with salt spray.

Bermuda Grass

• Bermuda grass (Cynodon spp.) grows well in tropical and subtropical regions. The genus contains nine species of grass, but many cultivars are available. It tolerates alkaline soil conditions well. It requires ample irrigation or rainfall to thrive. The grass is widely used as a lawn, in parks and in sports fields. It tolerates heavy foot traffic and salinity and can withstand drought with ease. The grass enters a semi-dormant state when it does not receive adequate water, but it quickly springs back to life once irrigation is restored.

Buffalo Grass

• Buffalo grass (Buchloe dactyloides), a hardy North American native grass, produces a dense sod. tolerates alkaline soil and grows in a wide range of conditions. It can withstand extreme cold, heat and drought. It enjoys full sunlight. The grass grows to a height of 4 to 6 inches and often produces unsightly seed heads. The grass makes a good lawn choice. It does well in parks and playing fields, and its dense root system helps control soil erosion.

Soil pH Control

• Consider lowering the pH of alkaline soil so the grass does better. Applying fertilizers that contain urea, ammonium nitrate, ammonium phosphate and ammonium sulfate to an established lawn will help acidify alkaline soil. Regularly applying nitrogen fertilizers over the seasons will help lower the soil's pH. Do not use fertilizers that contain bone meal, calcium cyanamide, calcium nitrate, potassium or sodium on lawns planted in alkaline soil or the soil will become more alkaline.