My compost is wet and smelly. I put veg peelings and grass clippings in the bin. Am I doing anything wrong?
Yes. Grass and veg peelings are soft and wet. The soil organisms that make compost need air and can’t tolerate water-logged conditions. So add in brown, fibrous stuff – crumpled or shredded paper, herbaceous prunings, hay or straw. This will break up the soggy heap and the woody material will soak up the surplus liquid. An occasional handful of top soil, crammed with living organisms, will make the heap work much better. [Remember spent commercial compost does not contain these organisms so should not be put in the compost heap, but should be used as a soil conditioner.]

‘I have ants in my compost bin.’
Ants will do no harm – they help break down the material. But your bin must be quite dry. You should add in sappy stuff like annual weeds or fresh grass clippings. During a hot spell, you might even need to water your heap! Circular bins sitting directly on the soil are the best design as the condensation quickly runs down the sides keeping the material moist. Square or hexagonal bins that have “fins” to keep the composting material away from the sides are more likely to dry out round the edges and will probably need an occasional bucket of water to keep the ingredients moist. The attractive ‘beehive type’ bin lets in far too much air, so can be a problem here.

‘I keep seeing mice in my bin’
Again the bin may be too dry. If you’re worried about this, place a layer of fine chick wire on the soil underneath your bin and this should prevent mice or voles from getting in. See our advice sheet Vermin.

‘Every time I open the lid a swarm of little flies comes out.’
They’re attracted to the rotting fruit peelings in the bin. Mask the smell by covering with a layer of fresh grass clippings or top soil.

‘Should I add in extra worms to make the bin work better?’
No. You may see some worms nestling round the damp lid of the bin, but otherwise you’ll find them down at the bottom. Composting goes through 2 stages – a hot, fast one followed by a cool, slow phase. To begin with, the heap will be too hot for the worms, but as it cools down they will simply come up from the soil to complete the composting process by chomping through the partly rotted material. When you look at a handful of finished compost, you’ll be amazed at how many worms have taken up residence!

Should I add citrus peel?
You can add orange and lemon skins to your compost bin. Although these peelings are too acidic for worms in a wormery, they break down readily in a compostabin or New Zealand box and will be well rotted before the worms at the bottom of the heap try to process them.