There are several ways you can use compost effectively. If you have been working your pile or tumbler for 3 to 4 months, and you have been turning it regularly, the compost should be finished. While composted manures contain higher levels of nutrients, most compost made from only yard waste and kitchen scraps has variable nutrient value and should be viewed as an effective soil builder and source of humus. Compost will help sandy soils hold water and nutrients so plant roots can use them, and it helps lighten clay soil so plant roots can penetrate. Regular applications of compost improve any soil type.
Use Your Compost
Verify if your compost is ready to use by pulling a handful out from the interior or bottom of the pile. If it is dark brown, crumbly and lightweight, and has a clean, earthy smell, it is ready to use. Compost that is wet and heavy or that still has an odor of decomposition is not ready to use. Turn the pile and check again in a few days.
Spread a layer of compost over your garden or beds before planting. Shovel it into a wheelbarrow to move large quantities easily. Compost is a soil conditioner, and should not be used as the sole planting medium; it is best mixed with soil. For a new garden, use a layer 4 to 6 inches deep over the planting area. If you have an established planting area where you have regularly added compost, a layer from 1 to 3 inches will be enough. Top off raised beds with fresh compost. In all applications, mix the compost into the soil before you plant.
Add a layer of compost around plants as mulch. Finished compost mulch will naturally combine with the soil while it blocks weed growth around your plants. Rain dissolves nutrients from the compost and releases them into the soil directly around your plants. Add more compost mulch as needed throughout the season. Two inches of compost is a good depth around most plants.
Make compost tea to use as liquid fertilizer for your plants. Fill a burlap bag with compost and tie it closed. Immerse it in a plastic tub or trash can filled with water. Allow it to sit for 3 or 4 days, stirring it every day. Remove the bag and empty its contents back into your compost pile. Dip out the compost tea and water your plants with it. The nutrients from your compost are already dissolved in the water and are immediately available for your plants to use.