What Can I Use Compost For?

Question: I’m starting a compost bin this season. What can I use compost for? How about grass? Should I spread compost on my lawn? -Randy T.

Answer: The most common use for compost is as a soil additive in the garden or for container plants. Adding compost to your planting medium makes the soil richer by boosting the nutrient levels and also improves the texture to help the soil retain water. When you are preparing a garden bed before the season begins, you can spread one or two inches of compost over the surface of the soil. Then mix the compost with the soil below to a depth of six to 12 inches. If your plants are already growing in an area where you want to add compost, you can use the side dressing technique instead. To side dress an area, spread the compost over the ground, but leave a few inches of room around any plants that are growing there. You need to leave this space between the plants and the compost to prevent problems from arising in the plants as a result of the microorganisms in the compost. The best time to do side dressing is in late spring or early summer, when plants are growing strong and can use the nutrients right away.

Most gardeners add compost to their garden beds and plant pots on a schedule ranging from every six months to every two years. If you are growing vegetables, you will need to feed your plants by adding new compost more frequently than if you are growing flowers. In regions where it gets cold in winter and there are two growing seasons, you should update compost once per year, in the fall before the ground freezes. If your area doesn’t get that cold, giving you one long growing season (like in the southern and southwestern United States), freshen your soil with new compost twice each year. Gardeners in these regions should apply compost before planting in the spring and again in late August or early September. Containers and window boxes should have a new dose of a one-inch layer of compost twice each year.

You can also use compost as a base layer for mulch around trees and shrubs. To mulch with compost, apply a layer between half an inch to one inch thick over the surface of the soil under your trees and shrubs, stopping at the drip line. Top the compost with two to three inches of your chosen organic mulch, such as shredded leaves or pine needles. The mulch on top of the compost both keeps it moist and holds it in place so it isn’t washed away by rain or wind.

Whenever you put a new plant into the ground, whether it’s a perennial or an annual, consider adding two to four cups of compost to the hole where the plant or bulb is placed. Using compost when you add new plants to the garden ensures that there will be plenty of nutrients available in the soil for your plants. Any plant that will produce a food harvest especially benefits from this treatment.

Using compost and sand, you can also create your own planting medium. (Optionally, you can use perlite instead of all or part of the sand, if you prefer it.) Simply mix one part compost to one part sand or perlite. You can do this in a wheelbarrow, or on top of a tarp. For a potting soil to fill containers, you can alternate one-inch layers of compost and sand or perlite, stirring them thoroughly to produce a uniform mixture when the container is full.

Your lawn benefits as much as your garden does from the nutrients in compost and its ability to condition the soil. If you’re putting in a new lawn, use a layer of compost two or three inches thick, and mix it into the top six to 12 inches of soil before planting the grass. If your lawn is already established, apply a quarter of an inch to half an inch of compost each year. You don’t need to mix the compost with the soil when you’re treating an established lawn. The compost will sift down through the grass to combine with the soil on its own in a couple of weeks. The best time to apply compost to your lawn is fall, followed by early spring as the next best time for the treatment. You can also treat bald spots by covering them with compost before you reseed the lawn in that area.

Should I spread compost on my lawn?

Yes, treating your lawn with compost is a great way to keep it green and healthy. If you are putting in a new lawn, spread a layer of compost that’s two to three inches thick over the top of the soil before planting the grass. Then dig to mix the compost into the top six to 12 inches of earth. Established lawns should get an annual refresher treatment of a quarter of an inch to half an inch of compost. You do not have to dig in the compost when you are doing a refresher treatment on an established lawn. It will settle in and meld with your soil as time passes, usually within just a couple of weeks. Fall is the best time to apply compost to your lawn, with the next best option being early spring. Bald spots in your lawn can be covered with compost before reseeding, too.

hands with compost on the lawn with text overlay how to use compost including the lawn