Compost

Compost is the ultimate garden fertilizer and best material available to enliven your soil. It contains virtually all the nutrients a living plant needs, and delivers them in a slow-release manner over a period of years. Adding compost to your garden is a long-term investment, helping to feed plantings for years.

Compost added to gardens improves soil structure, texture, aeration, and water retention. When mixed with compost, clay soils are lightened, and sandy soils retain water better. Mixing compost with soil also contributes to erosion control, soil fertility, proper pH balance, and healthy root development in plants.

Decomposition occurs naturally when organic remains are attacked by microorganisms and invertebrates in the soil, and it is decomposed to humus. Decomposition can be encouraged by creating ideal conditions. Fast or "active" composting can be completed in two to six weeks (versus typical 10 to 12 weeks). This method requires three key activities; 1) "aeration," by turning the compost pile, 2) moisture, and 3) the proper carbon to nitrogen (C:N) ratio. Attention to these elements will raise the temperature to around 130F, and ensure rapid decomposition.

Almost any organic material is suitable for a compost pile. The pile needs a proper ratio of carbon-rich materials, or "browns," and nitrogen-rich materials, or "greens." Among the brown materials are dried leaves, straw, and wood chips. Nitrogen materials are fresh or green, such as grass clippings and kitchen scraps.

Mixing certain types of materials or changing the proportions can make a difference in the rate of decomposition. Achieving the best mix is more an art gained through experience than an exact science. The ideal ratio approaches 25 parts browns to 1 part greens. Judge the amounts roughly equal by weight. Too much carbon will cause the pile to break down too slowly, while too much nitrogen can cause odor. The carbon provides energy for the microbes, and the nitrogen provides protein.

 Troubleshooting guide -

Finished compost is dark in color and has an earthy smell (the smell of soil). It is difficult to recognize any of the original ingredients, although bits of hard-to-decompose materials (such as straw) sometimes can be seen. If the compost contains many materials which are not broken down, it is only partly decomposed. Adding partly decomposed compost to the soil can reduce the amount of nitrogen available to the plants. The microorganisms will continue to do the work of decomposing, but will use soil nitrogen for their own growth, restricting the nitrogen's availability to plants growing nearby. If partly decomposed compost (large pieces) are returned to the composter, microorganisms will jump-start the composting process as new material is added.

Compost will condition soil whether it is spread in a layer on the soil surface or is dug in. A garden soil regularly amended with compost is better able to hold air and water, drain more efficiently, and contains a nutrient reserve that plants can draw on. Amended soil also tends to produce plants with fewer insect and disease problems. The compost encourages a larger population of beneficial soil microorganisms, which control harmful microorganisms. It also fosters healthy plant growth, and healthy plants are better able to resist pests.

Add a small amount of compost to the planting hole of small perennial plants and annuals for future benefits.

To bolster poor soil with little organic matter, spread 2 to 3 inches of compost over a newly dug surface. Then work the compost into the top 6 inches of earth.

A garden soil that has been well mulched and amended periodically requires only about a 1/2 inch layer of compost yearly to maintain its quality.