Lawns can become damaged by pets or cold weather, making regrowth difficult. Using gypsum, also known as calcium sulphate, can help repair lawns and allow better grass root establishment. Gypsum can also be applied to any soil before seeding, to help new grass grow stronger and retain moisture for longer periods of time.
Apply gypsum on soil, before spreading grass seeds for a new lawn. Till the soil with a manual tiller for small areas or a rototiller for larger areas. After the soil has been loosened, spread 136 Kilogram of gypsum granules for every 1,000 square feet of soil, with a hand held lawn spreader or broadcast spreader. Spread the granules evenly, then work into the soil with a rake. Water the soil immediately after applying the gypsum.
Spread a layer of gypsum granules with a broadcast spreader evenly over existing lawns. Apply 18.1 to 22.7 Kilogram of gypsum granules per 1,000 square feet, two times a year, to help break down compacted soils such as clay. Water the lawn after each application. The granules will slowly penetrate into the soils and permit air to circulate through it. Grass roots will establish better, allowing the grass to grow stronger.
Place a thin layer of gypsum granules with a hand-held lawn spreader, over stained areas of your lawn caused by pet urine. Some pets have very acidic urine and may cause burn spot on lawns. Applying gypsum over the stains will help neutralise the salts from the urine, allowing the grass to regrow or prepare it for reseeding.
Distribute gypsum granules over lawns after the use of salt to melt snow and ice during the winter months. The salt used to melt snow and ice may have a high levels of potential Hydrogen (pH), which can seep into the soil and damage lawns. Spreading a layer of gypsum using a drop spreader or a broadcast spreader, both used for lawn seeds or fertiliser, can help neutralise the salt in the soil and repair your lawn.
Follow the instructions on the gypsum bag label for proper applications. Gypsum can be applied to stubborn soils up to four times a year, to help loosen it.