Compost bins compared
The container is the decision most people make first, and it matters less than they expect. The same greens and browns, kept damp and given air, turn into compost in almost any container. What the container changes is how much space it needs, how warm and moist it stays, how easy it is to turn, how well it keeps animals out and how much work it takes to empty. This page compares the common options so you can match one to your garden, your household and the time you have.
The options at a glance
| Container | Space needed | Effort | Speed | Keeps animals out | Best for |
|---|---|---|---|---|---|
| Open heap | A corner of a garden | Low | Slow to medium | No | Large gardens with lots of leaves |
| Closed bin | About one square metre | Low to medium | Medium | Mostly | Most home gardens |
| Three-bay system | Several square metres | Medium | Medium to fast | Partly | Keen gardeners with lots of material |
| Tumbler | A patio or path | Medium | Medium to fast | Yes | Small gardens, people who dislike forking |
| Worm bin | A cupboard or balcony | Low | Medium | Yes | Flats and kitchen scraps |
| Bokashi bucket | Under a sink | Low | Fast first stage | Yes | Kitchens with no garden yet |
Open heaps
An open heap is the oldest method: material piled in a corner, sometimes held in by a few posts and wire. It costs nothing, holds a great deal and is easy to turn with a fork. The open sides let air in and let rain soak the heap, which can be good in a dry climate and less good in a wet one. Open heaps do not keep out rodents, foxes or dogs, so they suit gardens where you compost mostly leaves and trimmings rather than kitchen scraps.
Closed bins
The familiar plastic cone or box with a lid and an open base is the most common home bin. It sits on bare soil so worms and other organisms can move in from below. The lid keeps rain off and heat in, and the walls keep most animals out, although a determined rodent can dig underneath. Closed bins are easy to add to but awkward to turn, because the walls get in the way. Many people simply add to the top and lift finished compost from a hatch at the bottom. Wooden slatted bins work the same way and breathe better than solid plastic.
Three-bay systems
A row of three open-fronted bays, usually built from timber or pallets, lets you run a heap in stages. You fill the first bay, turn its contents into the second when it is full, and move it again into the third to finish. Turning between bays mixes and airs the material well, and the system handles large amounts. It needs space and some building, and it rewards people who enjoy the work. It is the most common choice for allotments and large vegetable gardens.
Tumblers
A tumbler is a drum on a frame that you turn with a handle. Turning is easy and quick, which keeps air moving through the material, and the closed drum keeps animals out entirely. Tumblers are off the ground, so worms cannot move in from the soil, and the drum can dry out or turn soggy faster than a heap on the ground. Most work best when filled in one batch and then left to finish, so many owners use two: one filling and one finishing. Capacity is smaller than a bin.
Worm bins
A worm bin uses composting worms, a different kind from the earthworms in your garden soil, to eat kitchen scraps in a shallow box. It is quiet, compact and odour free when it is looked after, which makes it a good fit for a balcony or a cupboard. The worms need moderate temperatures, a steady supply of food and bedding such as shredded paper, and they dislike citrus, onion and large amounts of anything at once. The result, worm castings, is rich and fine. Our page on small-space composting covers worm bins in more detail.
Bokashi buckets
Bokashi is not composting in the usual sense. Kitchen scraps, including cooked food, go into an airtight bucket with a bran treated with fermenting microbes. After a couple of weeks the contents are pickled rather than rotted. They still need to be buried in soil or added to a heap to finish breaking down. Bokashi suits kitchens that produce a lot of scraps and households without a garden heap yet, as long as there is somewhere to put the fermented material afterwards.
Choosing
Start with the material you have and the space you can give. If you have a garden and mostly leaves and trimmings, an open heap or a three-bay system is hard to beat. If you mostly compost kitchen scraps in a small garden, a closed bin or a tumbler keeps things tidy. If you have no garden at all, look at a worm bin, or bokashi with a plan for the fermented material. Many households combine two: a worm bin or bokashi for the kitchen, and a heap for the garden.