Garden composting
How to make a compost bin
Composting is one of the most valuable things a gardener can do. A well-managed compost heap turns kitchen peelings and garden waste into rich, free soil improver that improves drainage in clay soils, retains moisture in sandy soils, and feeds plants naturally. The key is balancing wet green material with drier brown material to keep the heap active without it turning slimy or smelly.
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Step-by-step guide
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Choose the right location
Site the compost bin in a sheltered spot that gets some sunlight to help warm the heap, but not full sun all day, which dries it out. Place it directly on bare soil rather than on paving — contact with the ground allows worms and microorganisms to enter from below, which are essential for decomposition. Allow enough space to stand beside it with a fork for turning. Keep it accessible from the kitchen for year-round use.
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Choose your bin type or build a simple bay
A plastic dalek-style compost bin is the most common choice in UK gardens and works well for continuous kitchen and garden waste. A wooden pallet bay or a simple three-sided timber frame is better if you have large volumes of material to process, as it is easier to turn. Many local councils in Kent offer subsidised compost bins — check whether your borough has a scheme before buying.
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Start with a coarse base layer
Before adding any waste, lay a 10 to 15 cm layer of coarse, woody material at the bottom — small twigs, straw, torn cardboard, or scrunched-up newspaper. This base layer lets air circulate from below and prevents the bottom of the heap becoming waterlogged. It also creates a habitat layer that worms and beetles will move into from the soil beneath.
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Alternate greens and browns in layers
Greens are wet, nitrogen-rich materials: vegetable and fruit peelings, grass clippings, coffee grounds, tea bags, annual weeds (not seeding), and fresh plant cuttings. Browns are dry, carbon-rich materials: cardboard, paper, dry leaves, straw, wood chip, and shredded prunings. Aim for roughly equal volumes of greens and browns. A heap that is too green turns slimy and smelly; too brown and it just sits there doing nothing.
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Keep the heap moist but not wet
The composting process needs moisture to work — the heap should feel like a wrung-out sponge when you squeeze a handful. In dry weather, water the heap lightly. In a very wet UK autumn or winter, cover the top with a piece of old carpet, cardboard, or a plastic sheet to stop it becoming waterlogged. If it gets too wet, add more browns to rebalance it.
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Add material in small pieces
The smaller the pieces added, the faster they decompose. Tear cardboard into strips, cut or shred plant material before adding, and avoid putting in whole cabbages or large brassica stalks whole. A garden shredder makes a big difference if you have a lot of woody prunings — shredded material composts in weeks rather than months.
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Turn the heap every few weeks
Turn the contents of the bin with a fork every three to four weeks — more often for a hot active heap, less often for a slower cold heap. Turning mixes the materials, introduces oxygen, and moves cooler outer material into the warmer centre. After turning, the heap will often heat up noticeably within a day or two, which is a good sign that decomposition is active.
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Know when the compost is ready
Finished compost is dark brown, crumbly, and earthy-smelling — like good forest soil. The original materials should no longer be recognisable, apart from occasional twigs or tough fibres. In a well-managed heap, kitchen and garden waste can break down in three to six months in summer; a cold winter heap may take nine to twelve months. Use finished compost as a mulch, dig it into beds, or mix it into potting compost.
Tips and common mistakes
- Never add meat, fish, cooked food, or dairy — these attract rats and create a smelly, anaerobic heap.
- Avoid adding diseased plant material or weeds that have set seed, as composting may not destroy all pathogens or seeds.
- Grass clippings are pure green — always mix them with a layer of browns when adding, or they will mat together and exclude air.
- Check your council's website: many Kent councils (including Dover District) offer subsidised compost bins for residents.
- A second bay or bin is useful once the first is full — you can leave the first to mature while adding fresh material to the second.
- If the heap smells bad, it is either too wet, lacks air, or has too much green material — add browns, turn it, and leave the lid off for a day or two.
Need a hand in the garden? Contact The Sandwich Handyman — Richard covers gardening jobs across Sandwich and East Kent, including setting up compost areas and general garden tidying.