Trench Composting in Garden

Compost

• Compost enriches garden soil by providing it with increased bulk. This bulk, the result of the decomposition of organic matter, provides some nutritional value for plants but also increases aeration, water and nutrient retention and good microorganism activity. The key to good compost is organic matter commonly found in kitchen scraps -- like coffee grinds, vegetable cuttings and eggshells. Some gardeners deposit these materials in bins or other containers and wait for the detritus to decompose and mature into garden ready compost. This compost is then interred throughout the garden.

Trenches and Pits

• Trench composting takes the same ingredients but instead of composting in bins, the raw, organic matter is dug in between garden rows and allowed to age in concert with maturing crops. The basic trench composting method requires you to dig a hole, or trench, to a depth of 12 inches. The trench or pile is filled with organic material as it become available. After depositing organic material, place 8 inches of soil on top of the hole or trench. Trenches can be dug alongside planting rows or near plants that require additional feeding. Pits are often dug in areas where soil is poor or compacted. As the organic matter decomposes, the soil is enriched and aerated.

English Method

• The English method is a variation of trench composting and is sometimes called "vertical gardening." This method involves a yearly rotation of three garden areas: the composting trench, the walkway and the planting row. During the first year of composting with the English method, plan your garden in 3-foot rows. The first row is the growing row, the second row is the walkway and third row is a 1-foot-deep trench filled with 11 inches of organic matter topped with 1 inch of soil. For the second year of the English method, the first row becomes the compost trench; the second row becomes the planting row; and the old compost trench becomes the walkway. For the third year, the first row becomes the walking space; the second row becomes the compost trench; and the third row becomes the planting row. This rotation ensures that the planting row receives fresh, renewed soil each growing season.

Considerations

• Choose compost materials carefully. Animal products like meat, fat, oil and butter attract vermin and can potentially cause disease. When using vegetative kitchen scraps or garden debris make certain to vary the types of matter placed in the compost trench. A large of amount of green material -- like grass clippings, branches and leafy products -- may cause a nitrogen build-up. Excess nitrogen causes odoriferous compost heaps. The odor is caused by a lack of oxygen, which also delays decomposition.