What Is Peat Compost?

Overview

Peat compost is compost that contains some form of peat. Compost is only one use for peat. Manufacturers commonly add peat to commercial soil and soil-less mixes. Peat is lightweight and sterile. It is a popular medium in which to germinate seeds and to grow seedlings. Peat will not compact around the seedling's roots or drown them in water.

Composition

To build a peat compost, the Canadian Sphagnum Peat Moss Association suggests that you add one layer of peat for every 4 inches of materials in your compost heap. One of peat's roles in the pile is to absorb excess moisture from the pile to keep the organic material moist but not soaking wet. Peat retains as much as 20 times its weight in moisture. Moist organic material helps to form the best compost in the least amount of time. Ideally, peat releases the moisture so that it is available when the pile needs extra moisture.

Compost

Gardeners do not actually make compost; they help the natural decomposition cycle along by combining ingredients together to foster the breakdown of organic materials. Successful composting means controlling nutrient balance, particle size, moisture content, oxygen flow and temperature, according to the U.S. Environmental Protection Agency. Mature compost is a very stable material. Gardeners use mature compost as a soil additive as well as a top mulch.

Peat

Peat is partially decayed or decomposed plant materials. Sphagnum peat moss is the most prevalent type used in horticulture. Sphagnum moss grows on the tops of bogs and wetlands. Peat drops down to the layers below. Peat harvesters clear away the top layers of the bog and vacuum out the peat. They drain part or all of the bog to facilitate the harvesting process. Sun and wind dry the peat, and the harvesters collect it and transport it for gardeners to use all over the world. Peat does not compact, while some compost does compact, according to Cornell University's Gardening Resources Guide. Air and roots do not have room to move around in compacted soil, and so compaction is not desirable.

Benefits

The Canadian Sphagnum Peat Moss Association states that adding peat to your compost will help you to make your compost better "by speeding up the process, reducing odors and controlling air and water in the compost pile." Peat, although poor in nutrients, helps to deliver nitrogen to the compost because it traps nitrogen that the compost pile would otherwise release as ammonia. The Association recommends people add several inches to the top of the pile to reduce odors coming from the compost. Gardeners need to reapply this top layer of peat after they aerate the pile.

Alternatives

Peat is not essential for good compost. Gardeners routinely produce excellent compost without adding peat to their organic materials. Control moisture without peat by monitoring the amount of water you add to the pile and let it dry out slowly and naturally. Control compost pile odors by not adding any meat or meat by-products to the pile. Add food wastes, fruits, vegetables, coffee grounds and other organic products to the center of the pile and cover them with other materials. Turn and aerate the pile on a regular basis.