Growing a thick and luscious lawn can be a bit of a balancing act.
Typical tall fescues and other turf type grasses grow best in pH neutral soils. On a scale of 1 to 14, a pH of 6.5 – 7.0 is the proper level for a healthy lawn.
If a lawn is out of balance, adding soil amendments in early or mid-spring can get you on the path to greener pastures.
Step 1: Have the soil professionally tested. Home testing methods may not be accurate enough to base a lawn care program on. Start with a professional test and compare it with the home test results to create a baseline for future home test readings.
Step 2: Soils with a pH level below 6.5 can be amended with granulated lime. Horticultural lime is a fast-acting powder and meant to be used in garden areas. Powdered-type limes are more difficult to spread and can potentially burn existing grasses. Dolomitic or pelletized limes are the best choice for amending turf type grasses.
Step 3: To raise the pH in existing lawns, spread 35 pounds of granulated lime over 1,000 square feet of lawn. Use a broadcast spreader to apply the amendment evenly and then water it in. A 35-pound application should raise the soil’s pH by 0.5 point. For lawns with a pH below 5.8, spread 50 pounds per 1,000 square feet in the spring. Avoid spreading more than 50 pounds of lime per 1,000 square feet at any given time, and do not spread lime in conjunction with nitrogen fertilizers.
Step 4: To lower the pH in existing lawns, use ammonium sulfate or urea based fertilizers. Apply the fertilizer per manufacturer’s directions. The use of ammonium sulfate or urea based fertilizers will gradually lower soil pH over the course of 3 years to 5 years.
Step 5: Use agricultural sulfur to quickly lower the pH in bare soils or existing lawns. In the spring, apply five pounds of sulfur per 1,000 square feet of grass and water it into the existing lawn. For bare spots, spread sulfur and then mix it into the top six inches of soil.
The health and appearance of lawns can be significantly improved by balancing the pH levels in soil. Too much lime or sulfur will damage lawns. Avoid over application of any soil amendment.