Trench Composting
Method
Trench composting puts kitchen scraps directly into the soil, where they rot out of sight and feed the life below ground. It is especially handy on an allotment or in a new vegetable bed with room to rotate crops. The method is tidy, low-tech and avoids handling a large compost heap.
How it works
Dig a trench about 20 to 30 cm deep, place a mixed layer of raw vegetable peelings, fruit scraps, coffee grounds and torn cardboard in the bottom, then cover it completely with soil. Soil organisms, worms and microbes break down the buried material while moisture is retained around it. Leave the trench for several weeks before planting, or use it in autumn for a spring crop. Deep coverage discourages flies and scavengers. Plant hungry crops such as beans or squash nearby once the contents have begun to decompose.
Details
Choose a bed away from roots of permanent plants and mark the trench so it is not disturbed too soon. Make narrow trenches between future rows, or fill a larger planting area gradually. Do not bury meat, fish, dairy, cooked food or dog and cat waste in a home garden, because they can attract vermin; some council schemes accept these separately. Avoid large woody pieces, which break down slowly, and do not bury material where you plan immediate root crops. If the soil is very wet or frozen, collect scraps temporarily in a compost bin instead.
Tips
Cover every addition with at least 10 cm of soil and wash hands after handling scraps. Rotate trench sites each year so no part of the plot becomes overloaded. Do not use manure, hay or grass that may contain aminopyralid weedkiller residues, particularly before growing tomatoes, beans or potatoes in that bed.
Trench Composting: frequently asked questions
How does trench composting work?
Dig a trench about 20 to 30 cm deep, place a mixed layer of raw vegetable peelings, fruit scraps, coffee grounds and torn cardboard in the bottom, then cover it completely with soil.
What do I need to know about trench composting?
Choose a bed away from roots of permanent plants and mark the trench so it is not disturbed too soon.
What are some tips for trench composting?
Cover every addition with at least 10 cm of soil and wash hands after handling scraps.
General guidance for UK gardens and allotments. Page updated 18 Sep 2026.