Optimizing Soil pH for St. Augustine Grass: A Complete Liming Guide

Understanding Soil pH and Its Impact on St. Augustine Grass

Soil acidity, measured on a pH scale from 0 to 14, plays a critical role in nutrient availability for turfgrass. A pH of 7 is neutral; values below 7 indicate acidity, while those above indicate alkalinity. Most turfgrasses thrive in slightly acidic soil (pH 6.0–6.5), but St. Augustine grass performs best in a slightly higher range. Maintaining the proper pH ensures essential nutrients remain accessible to the roots.

Why Liming Matters for Your Lawn

In many regions, native soils are more acidic than St. Augustine grass prefers. Garden lime neutralizes excess acidity, creating a more favorable growing environment. While lime can be applied any time of year, the key question is how much to apply.

Determining the Right Lime Quantity

A general guideline is 40 pounds of lime per 1,000 square feet, but this is only an approximation. The only reliable method is a soil test through your local county Extension service. Over- or under-liming can harm your lawn long-term—don't guess, test!

Choosing Between Powdered and Pelletized Lime

Both forms are equally effective, but they differ in handling and cost:

• Pelletized lime flows easily through a spreader.
• Powdered lime is slightly less expensive.

Can Lime Be Applied with Fertilizer?

Q: Can I put down lime when I spread fertilizer on my lawn?
A: Yes. As long as the turf is dry, the particles won't stick to grass blades. They'll fall to the soil and begin working as soon as it rains.