The compost trench is an efficient way of disposing of old plant material. In this trench you can add almost any plant or kitchen waste, at any time of the year. That is why the composting trench is a method preferred by most gardeners for use over the autumn and winter months when the temperatures are low and a compost heap may not be very active.
The most convenient place for trench composting is in vegetable plots because vegetable gardening takes a lot of nutrition out of the soil and this loss must e replaced to feed the next crop. Often, several trenches can be open and in use at the same time to cater to the crop rotation system within vegetable garden and to reduce the risk of pests or diseases carrying over from one crop onto the next.
Another favorite place for trench composting is the site of new rose, tree and shrub borders in order to improve soil fertility.
If you are going to use this composting method in your garden you can start in late summer or early autumn, when plant debris, vegetable scraps and kitchen waste are plenty. Mark off the area that is to e dug over in a series of trenches and mark the lines of the first two parallel trenches.
Dig a single trench about 30 cm wide and deep and move the soil from the trench to the end of the plot, which will be the very last section to be trenched. Gradually fill the trench with plant debris, vegetable scraps and kitchen waste, as they become available.
Dig a second trench in the same way as the first one. Cover each additional layer of material from the first trench with the soil that has just been dug from the second parallel trench. After the first trench is full and the second one has been dug, start filling the second trench by creating a third trench.
Each completed trench will gradually settle over a month or two as the plant material decomposes. Woody material, such as cabbage stems or prunings, will decompose faster if it is shredded before added to the trench. Also, if you want to speed up the whole process, you can add small amount of nitrogenous fertilizer to the trench.