Common composting problems

Difficult to turn or extract compost from the bin

The reason for turning the compost is to ensure that sufficient air is able to assist the composting process. There is no need to undertake a major digging operation in order to ensure that this happens. All that is required is that you either make use of the compost aerator, available from most garden centres, or just twist the fork and then withdraw it.

Ants / flies / woodlice in the bin

Woodlice are beneficial to the composting process and indicate that the material is breaking down into compost. Generally, the woodlouse feeds on decaying vegetable matter. They are not a problem, since they do not usually attack growing plants.

Ants are taking up residence because the conditions in the compost bin are ideal for setting up home. One of the best ways of dealing with the is to regularly disturb the contents (see above for how to turn compost). Ants will not live in regularly disturbed soil or compost.

Flies and midges are attracted by fruit and vegetables that have been put into the bin. There are two ways to deal with them. The first is to spread a thick layer of soil on top of any fruit placed in the bin. This denies flies access to the rotting material.

One other method that I have found very successful is to place one of the sticky yellow fly traps – usually used in greenhouses – in close proximity to the compost bin. The flies are attracted to this rather than the contents of the bin and become trapped.

The compost is produced at a slower rate than expected

The length of time needed to produce compost varies with the ambient temperature and the type and size of the material in the bin. The finer the material, the faster the rate of composting. Ideally, all woody material should be chopped into pieces no longer than 5 cm in length and a smaller garden shredder is invaluable, though not essential, in processing woody material.

The bin attracts rodents

As with ants, rodents are attracted to a warm and undisturbed environment. (I assume that you are not putting cooked meat waste into the composter). By regularly disturbing the contents, the rodents are discouraged from taking up residence.

If this fails, one other tip is to spread a piece of wire netting across the soil under the compost bin. The netting should protrude at least 16 cm beyond the bin on all sides.

With some compost bins, you can purchase a plastic base which sits on the soil with the compost bin on the top. This allows drainage and access to beneficial worms and soil insects, whilst at the same time, denying access to rodents.

The compost is too dry / too wet

The end product should be quite moist. Do not expect the same consistency of material that you might find in a bag of general purpose compost purchased from a garden centre.

To dry out compost that is too wet, add dry material such as shredded paper to the bin.

If the compost is too dry, then add water, but not too much or the temperature in the bin will fall and the composting process will slow down.

The compost bin is not big enough / is too big

The bins have been specifically designed to be the optimum size for composting material as quickly as possible. If you find that you need a bigger bin I would suggest getting a second bin. Not only will you find that you have extra capacity, you will also find that it is far easier to manage two bins than one.

If you find that the bin is too large, you could always ask a neighbour if they would be kind enough to supply you with some of their garden waste. You never know, you may even find a new friend!

The lid / bin blows away in strong winds

Placing a brick on top of the bin can solve this problem.

Compost bin smells and attracts flies

This problem usually arises when food waste is left on top of the compost pile. Quite often this will attract fruit flies in particular. There are two methods of control, the first being to attach one of the yellow greenhouse flytraps to the underside of the compost bin lid, or position it close to the outside of the compost bin. Alternatively, sprinkle a layer of soil on top of any fruit waste that is placed in the compost bin.

Compost is a slushy mess

Two main reasons for this problem are uncovered compost allowing rain in which cools the compost rapidly and stops the composting process. The other cause is putting too much “hot” waste in altogether. The solution to these problems are to have a cover on the compost pile or bin, and to ensure an adequate mixture of “hot” waste such as grass cuttings, with “cold” waste such as prunings or even torn up paper or cardboard.

Grass cuttings

Grass cuttings must be mixed with other, bulkier materials to allow air to circulate through the grass cuttings. One of the best materials for this is torn, shredded newspaper.

Compost heap is taking forever to decompose

Try giving the contents of the bin a good mixing. If the process has stopped, this will usually get it going again. The composting process will take longer during cold weather. You can use a compost activator if you wish, but possibly the best activator of all is urine.

Rats and mice are in my compost bin.

This is caused by adding meat or fatty food waste. Meat, bones and fat should never be included in the compost bin.

Compost heap smells of ammonia

I would suggest that this may be because you are adding waste from animal bedding. Not a good idea, since some animal waste is very damaging to plants unless it is “weathered” for a long time. This condition can also occur when too much soft green waste (such as grass cuttings) is added. Try mixing with prunings, paper, leaves or straw which has been chopped.