Healthy soil is key to having a healthy lawn, regardless of whether you're starting your lawn from seed, plugs or from sod. Compost, the crumbly soil amendment made from decomposed organic matter, creates the optimal soil structure that grass loves and should be mixed into your soil immediately before installing your sod. While you can buy commercially prepared compost, you can also make it at home with everyday garden waste. Start composting three to four months before you plan to install your sod to ensure your compost is ready in time.
Choose a location for your new compost pile. It should be flat, free of weeds and debris, and out of direct sunlight. If you're worried about how your compost pile will look, tuck it away in a place that's not in your direct line of vision, such as behind a row of tall flowers.
Create a foundation for your compost pile by putting down a 3-inch-thick layer of very coarse organic matter, such as chopped plant branches and dried corn stalks. This allows air to move under your compost pile while also allowing excess moisture to drain out of the pile.
Add a layer of small, shredded pieces of dried plant material, such as chopped leaves and dried grass clippings. This layer should measure approximately 9 inches in thickness.
Top the dried plant material with a 9-inch-thick layer of green, organic waste, such as fresh grass clippings, plant trimmings from your garden, flower cuttings or vegetable scraps from your kitchen.
Sprinkle 1 cup of 10-10-10 or 12-12-12 fertilizer over the top of your pile. This boost of nitrogen speeds up the decomposition process so you can harvest the results of your compost pile faster.
Cover the pile with an inch of soil from your yard. The soil adds beneficial microorganisms that further speeds up the decomposition activity in your compost pile.
Mix the pile with a pitchfork to evenly combine the dried organic material, the moist organic material, the fertilizer and the soil.
Squeeze a handful of the resulting mixture of organic matter to check for moisture levels. The perfect moisture balance is when you can just barely squeeze a drop of moisture out of the mixture. Monitor the pile weekly, and water it when appropriate, using enough water to get it to the perfect moisture level as determined with the squeeze test.
Allow the pile to sit for five weeks, then turn it with a pitchfork to mix the contents and move the organic matter that was previously on the edge of the pile into the center of the pile. Repeat this mixing process every five weeks.
Harvest your compost when it's dark, crumbly and looks more like soil than the original organic material. This generally takes three to four months.
Spread the compost over the surface of the bare soil where you plan on installing sod, using approximately 1/2 cubic yard of finished compost for every 500 square feet. Mix the compost into the top 8 inches of soil immediately before planting your sod.