BLUE SPRINGS, Mo. - Many gardening difficulties are rooted in substandard soil. The good news is that whether your garden has a nutrient, moisture or aeration problem, you can improve the soil with compost, said a University of Missouri Extension horticulture specialist.

"While it is unlikely that the nutritional requirements of the garden will be satisfied by adding compost, an application can greatly reduce your fertilizer inputs," said Marlin Bates.

Compost improves the texture of heavy clay soils, allowing greater water infiltration and air movement and making the soil easier to work. As organic matter breaks down, nutrients become soluble, making them available to plants when you add finished compost to the soil.

Waste generated from your household and yard will easily provide enough organic matter to warrant composting. Plant materials, including sod, grass clippings, leaves, hay, straw, weeds, sawdust and hedge clippings, are suitable for composting. Household refuse such as newspaper, vegetable scraps and coffee grounds are also good additions. Items you should avoid composting include weeds heavily laden with seeds, diseased plant material, grease, fat, meat scraps and bones.

Bates recommends placing a compost bin in a shady spot near a water supply. Shade helps the compost retain moisture. Put the bin on a well-drained site near the garden to reduce the distance that you have to transport the finished compost.

Once you select an appropriate site, decide what kind of structure to use, if any at all. You can simply create a heap of compost on the ground without any confinement, though this method is usually more unsightly. This type of compost heap should be at least 5 feet by 5 feet, with a minimum height of 3 feet.

If you are going to use a bin, there are several types that you can buy or make yourself. A bin with removable sides, or only three permanent sides, makes it easier to turn the compost, which speeds up decomposition.

The length of time needed to form compost can range from several weeks to several months. Different sources of composting material decompose at different rates. Grass clippings, for example, decompose more quickly than woody stems. The carbon-to-nitrogen ratio of the plant material also affects the rate of decomposition. Other factors include aeration, moisture and temperature.

Now is the perfect time to start composting. With the organic materials you will accumulate this summer and fall, you should have quality compost to enrich your garden next spring.

An MU Extension guide, "Making and Using Compost" (G6956), is available online at .