Common composting problems

Difficult to turn or extract compost from the bin

Compost is turned to ensure that sufficient air is in the material to aid the composting process. There is no need to undertake a major digging operation.  To turn compost, place a fork in the middle of the bin from the top, twist and lift as much as possible.

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 feed on decaying vegetable matter. They are not considered a problem.

Ants are taking up residence when the bin is too dry.  Disturb the ant nest with a fork and add more green/ wet material such as grass.

Flies and midges are attracted by fruit and vegetables that have been put into the bin. Spread a thin layer of soil on top of any fruit placed in the bin. This denies flies access to the rotting material.  

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.

The bin attracts rodents

As with ants, rodents are attracted to a warm and undisturbed environment. By regularly disturbing the contents, the rodents are discouraged from taking up residence. Place the bin close to the back door as possible as rats don’t like humans. Also, place the bin a foot / 30cm away from the edge of the garden so that any rats running past won’t be distracted by the bin.

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 more greens, such as grass cuttings.

The compost bin is not big enough / is too big

Compost 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, get a second bin. Not only will you find that you have extra capacity but it is far easier to manage two bins than one.

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 or the mix of dry to wet material is out of balance. Quite often this will attract fruit flies, in particular. Sprinkle a layer of soil on top of any fruit waste that is placed in the compost bin to reduce the fly problem and introduce more dry materials such as leaves, prunings, cardboard or scrunched up newspaper, and mix in.

Compost is a slushy mess

The main reason is too many greens. To rectify, add more dry/ brown material such as prunings, leaves and scrunched up paper or cardboard. Another reason could be that the compost bin does not have a lid, this allows rain to get in which cools the heap, slows down the composting process whilst allowing it to remain too wet. Place a cover or lid on the compost pile or bin and add some brown material to help soak up the moisture.

Grass cuttings

Grass cuttings must be mixed with other dry / brown materials to allow air to circulate through the grass cuttings. The best dry / brown materials are leaves, prunings and scrunched newspaper and cardboard.

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. Compost will take longer to mature during cold weather. Grass clippings are good at kick starting the bin but must be mixed well with dry / brown materials such as leaves, prunings and scrunched newspaper and cardboard, to provide air pockets.