How to lime a lawn
Lime raises soil pH. Apply it only when a laboratory recommends it for your grass. Moss, pale leaves and thin turf do not by themselves show that a lawn needs lime.
What you need
Soil report, agricultural or garden limestone, tape measure, scale, compatible spreader, broom, gloves and the product’s recommended eye/dust protection.
Step by step
- Choose the lime from the report. Calcitic lime supplies calcium; dolomitic lime also supplies magnesium and is useful where magnesium is low. Pelletized lime can be easier to spread. Do not use caustic builders’ or hydrated lime on the lawn.
- Calculate the total. Multiply the recommended rate by your lawn area. For example, 40 lb per 1,000 ft² on 2,000 ft² requires 80 lb. A separate metric example: 200 g/m² on 100 m² requires 20 kg. Do not apply a second soil-texture adjustment to an already calculated lab recommendation.
- Plan any split applications. Follow the report and product limits. A conservative established-lawn limit is 50 lb per 1,000 ft² at one time (about 244 g/m²). A recommendation of 120 lb per 1,000 ft² needs more than two applications at that limit. Confirm the spacing and retest plan with the lab; six months between applications is a common approach.
- Clear leaves and mow if needed. Apply at the normal mowing height. If compaction also needs core aeration, lime can follow it when that work suits the grass’s growing season. Aeration is not a prerequisite for liming.
- Calibrate the spreader. Weigh the amount delivered over a measured area. For two perpendicular passes, calibrate each to half the planned application rate. A fertilizer dial setting is not automatically suitable for lime.
- Spread evenly. Walk at the calibrated pace and lane spacing. Close the hopper at stops and turns. Collect spills and sweep lime off paths without leaving piles on the grass.
- Water and record. Follow the product’s watering directions to wash dust off blades and help pellets break down. Avoid runoff. Record product, area, amount and the next check date.
After the job
Expect changes over months, not days. Retest on the lab’s schedule, commonly after 6–12 months, using the same sampling depth and season where practical. Do not add more just because the lawn has not changed colour.
Keep lime and fertilizer as separately measured jobs and follow their compatibility instructions. Some nitrogen formulations and surface conditions increase ammonia-loss risk; there is no universal two-week interval for every combination. Ask the lab or manufacturer if the products’ directions are unclear.
Products that do a different job
Gypsum is calcium sulfate, not a carbonate liming material; do not use it to raise pH. Wood ash can raise pH, but its strength varies and a lawn-lime rate cannot be transferred to it. If the report says pH is already suitable, skip lime. Correct shade, drainage or nutrition instead if those are limiting growth.
Video example
Common questions
Does moss mean the lawn needs lime?
No. Moss can occur at different soil pH levels. Lime only if a soil test recommends it for the grass you grow.
Can I put down the whole lime recommendation at once?
Only if it is within the lab and product’s single-application limits. Larger totals need multiple appropriately spaced applications; simply halving every large recommendation is not enough.
Keep your lawn-care plan together
Use Lawn Care AI to organise care for your lawn and keep track of the jobs you have planned.
Sources and further guidance
- Purdue University Turfgrass Science — Changing soil pH under turf
- University of Arkansas Cooperative Extension — Liming Your Lawn (FSA-6134)
- Clemson Home & Garden Information Center — Changing the pH of Your Soil
- Iowa State University Extension — The Use of Gypsum and Lime on Lawns and Gardens
- Royal Horticultural Society — Lime and liming
- Montana State University Extension — Factors Affecting Nitrogen Fertilizer Volatilization
- University of Maryland — Lime types and split applications