How to make compost at home in about 30 days

Good compost is the single best thing you can give a garden. It feeds plants slowly, helps sandy soil hold water, loosens heavy clay and brings soil back to life. The good news is that you do not need a big garden or special equipment to make it. With the right mix and a little attention, kitchen scraps and dry leaves turn into usable compost in about four to six weeks.

What you need

• A container of about 80–150 litres: a compost bin, a large plastic drum with holes drilled in the sides and base, or two stacked clay pots (the traditional khamba style)
• A steady supply of kitchen scraps
• Dry "brown" material: fallen leaves, shredded newspaper, cardboard, sawdust or dry grass
• A small amount of finished compost or garden soil to introduce microbes
• A stick or small garden fork for turning

Get the balance right: greens and browns

Fast compost depends on feeding the microbes a balanced diet.

Greens are moist and rich in nitrogen: vegetable and fruit peels, tea leaves, coffee grounds, fresh grass clippings and green plant trimmings.

Browns are dry and rich in carbon: dry leaves, cardboard, paper, straw and sawdust.

Aim for roughly two to three parts browns to one part greens by volume. Too many greens makes the pile wet and smelly; too many browns makes it slow. Leave out meat, fish, dairy, oily food and cooked leftovers, which attract pests and smell as they rot.

Step by step

1. Start with a base. Put a 10 cm layer of twigs or coarse browns at the bottom of the bin for airflow.
2. Chop everything small. The smaller the pieces, the faster they break down. Tear cardboard and roughly chop large peels.
3. Layer and mix. Add a layer of greens, cover it with a thicker layer of browns, then sprinkle a handful of soil or old compost. Repeat until the bin is about three-quarters full.
4. Check the moisture. The mix should feel like a wrung-out sponge. If it is dry, sprinkle water as you layer. If it is wet and smelly, add more browns.
5. Let it heat up. A well-built pile warms up within two or three days as microbes get to work. Warmth in the centre is a sign it is working.
6. Turn it every three to four days. Mix the contents thoroughly with a stick or fork, moving the outside material into the middle. Turning adds oxygen and keeps the pile hot.
7. Stop adding fresh scraps. For the fastest results, start a second bin for new scraps once the first is full, so the first batch can finish.

When is it ready?

Finished compost is dark brown, crumbly and smells like a forest floor. You should not be able to recognise most of the original materials, although a few twigs or avocado stones may remain. Sieve those out and put them back into the next batch.

In warm weather, a carefully balanced, regularly turned bin is usually ready in four to six weeks. In cooler months, or if you turn it less often, allow two to three months.

Common problems

Problem	Cause	Fix
Bad smell	Too wet or too many greens	Add dry leaves or cardboard and turn
Nothing is happening	Too dry or too many browns	Add water and fresh greens, then turn
Fruit flies	Exposed food scraps	Bury scraps under browns and cover the bin
Ants	Pile is too dry	Water lightly and mix

Using your compost

Mix one part compost into three parts potting soil when planting, or spread a 2–3 cm layer on the surface of pots and beds as a top-dressing. Most plants appreciate a fresh layer at the start of each growing season.

Composting turns waste into one of the most valuable things in your garden. Once it becomes part of your weekly routine, you will wonder how you ever gardened without it.