Composting is central to a good wildlife garden. Even though councils now collect kitchen and garden waste, by putting your peelings and cuttings on the kerbside you are doing yourself out of a valuable resource.
“Anyone can compost and you can keep it very simple, just doing it as and when you can,” says Paul Alexander, head of horticultural and environmental science at the Royal Horticultural Society. “Lots of people get caught up in the dos and don’ts, but these ‘rules’ are based on optimising the process. If you can’t meet them, it simply means that decomposition will be slower.”
Composting not only ticks a sustainability box, but since the whole decomposition cycle relies on vigorous plant and animal life, it will also improve the biodiversity of your garden. Peer into the top layer of a nicely sweltering open heap and you’ll see a multitude of busy invertebrates and their predators, which in turn will attract birds and small mammals. Compost heaps also make perfect refuges for species such as toads and slow-worms. Here’s the basics of getting started with your heap, pile or bin.
1. CHOOSE A TYPE OF HEAP
There are three main approaches to compost – black plastic ‘Dalek’ bins; square wooden slatted bins; and open heaps. Each has pros and cons (slatted wooden bins allow greater airflow but are exposed to the elements; Daleks are sealed but can be unsightly; open heaps are messy but attract wildlife), so it’s down to personal preference. “We once compared the resulting compost from all three methods, and found little difference,” says Paul. “Quality is determined more by volume – bigger heaps produce more heat, which aids decomposition.”
2. PILE ON THE PEEL
Anything organic can be composted (with a few exceptions). Aim for a balanced mix of nitrogen-rich greens (grass, vegetable peelings) and carbon-rich browns (stems, cardboard, dead leaves). “Ideally you’d fill your bin in one go, cover it, turn it occasionally and leave it,” says Paul. “But in small gardens this isn’t realistic. Just add to it as and when you can, layering your browns and greens if possible, and keep it covered. Within 12 months it will have decomposed. Turning speeds up the process, but isn’t essential.”
3. KEEP IT BALANCED
If you have a glut of greens, such as grass clippings in summer, you can balance them out with browns such as scrunched newspaper or egg boxes. This will introduce air pockets and prevent your heap from compacting. The creatures that break down your material will find their own way in, from the micro-organisms and bacteria that naturally occur in plant matter to macrofauna such as worms and beetles. “Some people introduce worms, but it’s not necessary,” says Paul. “Plus they won’t hang around if conditions aren’t right.”
4. REAP THE REWARDS
After 12 months, separate out the rotted material – a beautifully rich, fine compost – and spread it over your soil. Anything that’s not broken down can simply go back on the heap. If you have enough space, it’s a good idea to have several bins. When one is full, you can leave the contents to break down and start filling another with fresh matter (chop up woody plant material first). It’s also beneficial to try more than one approach to composting – having an open pile as well as a bin will encourage more wildlife to your garden.
SEVEN TOP COMPOSTING TIPS
1. Site your bin on bare earth to encourage micro-organisms inside. A concrete base has to be traversed by invertebrates and will become stained if liquid leaches out.
2. You can site your bin in sun or shade, though compost in a sealed black plastic bin will warm up more quickly in the sun. Also think about ease of access from your kitchen.
3. Cover your heap in winter, as cold rain slows decomposition.
4. Keep your heap moist in summer. You can remove the cover to let light summer rain in, or keep it covered and add a little water now and then.
5. If your compost becomes wet and sludgy, add more browns. If it’s too dry and fibrous, add more greens.
6. Don’t include pernicious weeds such as couch grass, creeping buttercup and bindweed; meat; bones; dog or cat faeces; cooked food (because this could attract rats); dairy products; fish; or glossy paper (as it has a plastic coating).
7. Do include vegetable and garden waste; manure and straw from herbivorous pets; tea bags; coffee grounds; shredded paper (though scrunched is better because it holds its shape and retains air pockets); hair; eggshells; and wood ash.
Visit www.rhs.org.uk for more information.
Slow-worms often use compost heaps as a breeding ground. © iStock
FOUR COMPOST-LOVING SPECIES TO SPOT
1. Rose chafer beetle With their beautiful, iridescent green colouring, rose chafers are a welcome sight in the garden. The larvae feed on decaying leaves and vegetable matter, and are common in compost heaps.
2. Common toad Toads are declining in our gardens. A warm, damp compost heap offers an ideal daytime retreat and perfect hibernation site in winter, providing protection from the elements and predators.
3. Brown centipede Centipedes are important predators and are regularly spotted in compost heaps, which they use as a hunting ground for their small invertebrate prey.
4. Slow-worm (above) Slow-worms often use compost heaps as a breeding ground. Take care when turning or using your heap in summer when females are giving birth, and in winter when they are hibernating.