Garden Doctor - When Compost Heaps Fail

Ken Thompson explains how to solve the most common compost problems

Composting is about the easiest recycling you will ever do. All green (or orange, yellow, purple or brown) garden and kitchen waste, including most tea bags and coffee grounds, can go straight on the compost heap. Even tough stuff like brassica stems can be added if they’re chopped or smashed up with a hammer or spade first.

When used as a mulch, homemade compost helps to suppress weeds, retain soil moisture in dry weather and protect soil from the damaging effects of heavy rain. Once incorporated into the soil (there is no need to dig it in, the worms will do that), it improves soil structure, helps to retain water and, as it breaks down, releases essential plant nutrients, such as nitrogen. But creating compost doesn’t always go to plan.

Making compost needs a mix of nitrogen-rich ‘greens’ and carbon-rich ‘browns’, but never forget it’s only a compost heap, not a soufflé. Compost animals and microorganisms need food (which comes from the heap itself), air and water, and many compost problems stem from too much moisture. Most kitchen and garden waste, especially piles of lawn clippings, tends to be wet and low on structure, which can lead to a heap that’s wet, airless and smelly. The solution is to add scrunched-up paper or card, such as egg boxes.