Converting your garden’s and other wastes into compost is both a joy and a challenge. You can do it for sure, but don’t expect the visible perfection you often find in many bagged composts. You will have a more lumpy material full of health-giving microbes, a stimulant for soil and your plants.
Compost heaps do not have to grow hot, for example, heaps of leaf mould decay slowly and with little heat, through fungal decay. It’s the same for all small compost heaps, piles of wood chips, materials gathered in cold months, and heaps with more brown than matter. The end product is as or more valuable than compost from hot heaps, because of high microbial content.
Lawn clippings, soil and shredded prunings of apple trees
Why therefore is heat often emphasised as a primary goal in the process?
- Partly it’s for speed: commercial operations make nice-looking compost in 4-6 weeks, even though it is still hot and immature.
- Partly it’s about killing weed seeds, which perish at temperatures above 50-55C.
- The heat comes from rapid bacterial multiplication when enough green matter has been added and oxygen is present. Maintaining heat requires regular addition of green and brown materials, and a heap larger than about a metre square.
In small gardens, you could accept that composting will be slower and more fungal, taking a year or so from start to finish.
My main tips are to keep excess rain off your heaps, to cut stems and twigs into pieces no more than 10cm long, and to become a scrounger!
Carrot seedlings emerging from a mulch of homemade compost
Adding wastes from other sources will speed up your composting process: look for any of
- coffee grounds,
- spent hops from breweries,
- kitchen or vegetable scraps from catering outlets
- shredded paper from offices.
Enclose your heap with either a plastic, dalek-shape bin, or for allotments and larger gardens you can tie pallets together at four corners. Best line them inside with cardboard, to retain moisture and warmth. When you place the pallets, put cardboard on weeds if there are a lot, to prevent weed roots and seeds invading the heaps.
Compost heap profile, 4 months since first additions in November
More details to follow, see also my website page on making compost.
Final tip you can add weeds of all kinds, roots of perennial weeds and potato + tomato leaves and stems affected by late blight.