Compost is ready for use when the temperature in the pile drops to the temperature of the surrounding air. Other signs are:
  • It smells earthy-not sour, putrid or like ammonia
  • It no longer heats up after turned or watered
  • It looks like dark soil
  • It's crumbly, and doesn't have identifiable food items, leaves or grass.
The pH is usually around 7.5, and it will have a C:N ratio ranging from 10:1 to 20:1.

Planting in compost before it is finished could damage plants. Undecayed carbon materials as wood chips or leaves uses nitrogen from the soil to continue decomposing, robbing it from the plants you grow. Undecayed nitrogen materials can harbor pests and diseases. Immature compost can introduce weed seeds and root-damaging organic acids.

Compost can be used in many ways in the garden. Coarse, semi-decayed woody material is suitable as mulch to put on top of the soil around the plants. It can be used as mulch around trees and shrubs, to keep the moisture in, to prevent weeds from growing around trees and shrubs. The decayed material is good for digging into the soil together with commercial fertilizers at preparation time. It can be used for installing new lawns. A fine-screened layer can be used for a top dressing on established lawns. It can be used in the planting areas of landscapes. It should be used extensively in vegetable gardens to improve the organic matter content in the soil. It can be used for houseplants, for starting seeds in planting beds or flats, or made into a compost tea for watering plants.

Compost Benefits

Using compost as mulch, in the soil or as potting media is beneficial in many ways. Compost contains a full spectrum of essential plant nutrients. You can test the nutrient levels in your compost and soil to find out what other supplements it may need for specific plants.
  • Compost contains macro and micronutrients often absent in synthetic fertilizers.
  • Compost releases nutrients slowly-over months or years, unlike synthetic fertilizers.
  • Compost enriched soil retains fertilizers better. Less fertilizer runs off to pollute waterways.
  • Compost buffers the soil, neutralizing both acid & alkaline soils, bringing pH levels to the optimum range for nutrient availability to plants.
Compost helps bind clusters of soil particles, called aggregates, which provide good soil structure. Such soil is full of tiny air channels & pores that hold air, moisture and nutrients.
  • Compost helps sandy soil retain water and nutrients.
  • Compost loosens tightly bound particles in clay or silt soil so roots can spread, water drain & air penetrate.
  • Compost alters soil structure, making it less likely to erode, and prevents soil spattering on plants-spreading disease.
  • Compost can hold nutrients tight enough to prevent them from washing out, but loosely enough so plants can take them up as needed.
  • Compost makes any soil easier to work.
Compost brings and feeds diverse life in the soil. These bacteria, fungi, insects, worms and more support healthy plant growth.
  • Compost bacteria break down organics into plant available nutrients. Some bacteria convert nitrogen from the air into a plant available nutrient.
  • Compost enriched soil have lots of beneficial insects, worms and other organisms that burrow through soil keeping it well aerated.
  • Compost may suppress diseases and harmful pests that could overrun poor, lifeless soil.
Healthy soil is an important factor in protecting our waters. Compost increases soil's ability to retain water & decreases runoff. Runoff pollutes water by carrying soil, fertilizers and pesticides to nearby streams.
  • Compost encourages healthy root systems, which decrease runoff
  • Compost can reduce or eliminate use of synthetic fertilizers
  • Compost can reduce chemical pesticides since it contains beneficial microorganisms that may protect plants from diseases and pests.
  • Only a 5% increase in organic material quadruples soils water holding capacity.
When that first batch of finished compost is ready to spread, congratulate yourself for your efforts because you are ecological minded, and know that organic waste materials should be recycled into the soil instead of being put in a garbage can. By recycling the organic materials, valuable nutrients and organic matter are recycled. You have helped alleviate the solid waste problem!