Compost may or may not be ready for use. In fact, compost that has been only partly prepared may harm the growth of plants by leaching nitrogen as it continues to decompose in the soil. Depending on the nature of the materials composting, it may contain materials toxic to plants. Some plants produce hormones that prevent other plants from growing near them and competing for nutrients in the soil. These need full composting to break down and be rendered harmless. How is one to tell when the compost is ready and to what uses may it be put?

As in many an endeavor, experience is a great teacher and an experienced composter will tell if the process is finished by the texture and smell of the product. However, if your are not sure there are a couple of ways to tell.

If you are hot composting and the pile has been active but has now cooled down, give it another turning, ensuring that the moisture content is correct for good composting, about the feel of a wrung out sponge. If the pile does not heat up after a day or two it is likely finished. Again, it should smell earthly sweet and have a crumbly texture. If it is finished use it and if it is not finished you have already turned it for the next heat and cool cycle.

An even more sure test is to take a sample of the compost, at least a good handful, and put it into a glass jar. Close the lid and place it in a warm, sunny location for about three days. Open the jar and take a smell. Sour smells mean the compost is not done and an earthy, rich smell means it is ready for use. If not done, you may either turn the pile or not but test it again in about a week. Once finished, compost may be used in a myriad of way.

At the end of the growing season or before it starts compost makes a great soil conditioner. As a rule of thumb one inch of compost is sufficient for soil that is already fairly good, and three inches for problem soil or a first year garden. One cubic foot of compost will cover 12 square feet of garden to one inch deep and four square feet of garden three inches deep. If about a third of a pile is lost during the composting process, a pile three feet high, wide and deep will produce about 18 cubic feet of compost. Fork the compost into the top three inches of soil and certainly no deeper than eight inches for best results.

During the season apply compost as a mulch for the growing plants. It will help to retain moisture in the soil and to suppress weeds. Use any where from one to three inches. Rainfall and watering will cause it to act as a slow release fertilizer as the water trickles through. Earthworms love it and will carry it down into the soil for you while they leave behind even richer castings for another plant boost.

For another plant boost during the growing season, make a compost tea by placing a good shovel full of compost in a burlap sack and placing it in a 5 gallon bucket of water in the hot sun for a week. Pour the resulting "tea" liberally over the plants to boost their growth. Unlike commercial liquid fertilizers, compost tea will not burn the plants and only encourage growth. The spent compost in the bag is still a good soil conditioner.

Whatever the use to which it is put, well finished compost will be loved by the garden and the gardener alike.

About the Author

An avid gardener for over 25 years, Darrell Feltmate brings to Compost Central a wealth of knowledge of making compost for the best garden ever. He has had compost piles over 25 feet long and others in neat bins. Some piles have finished in as little as two weeks. Over the years many shavings from his wood turning have been compost for the garden.