Our compost bins go into hibernation during the winter. The optimum temperature for organisms in a compost bin, like bacteria and fungi, is 25-30C, so they function very poorly when it’s much lower.

In summer, the heap in the compost bin quickly sinks so there’s plenty room for more kitchen and garden waste, but the pile stays stubbornly high over the next few months. So what do you do?

Start by deciding what should or shouldn’t go in. All raw, but never cooked, kitchen waste composts well, including onion skins, leek trimmings and orange peel.

Don’t believe the myth that you’ll damage worms by adding this: you’d have to fill the bin with them to put worms off.

Fruit and veg from the supermarket is often trimmed up, leaving you much less to deal with than growing and preparing your own produce. Even so, you’ll still have some raw waste such as potato and carrot peelings.

They can make a dense, soggy and relatively airless heap. Anaerobic bacteria which emit an unpleasant odour move in, rather than the more agreeable aerobic bacteria. To prevent a nasty smell, break up the heap by adding in paper like crumpled envelopes and card such as toilet roll inners and ripped up cardboard boxes.

But some biodegradable material takes years to rot down, so may need to be consigned to green waste collections. Moss, bracken, and sawdust are also slow rotters. And any diseased plants or pernicious weeds such as bindweed, should also be binned.

Do try to keep adding waste to the compost bin as this slightly increases its working temperature. Before writing this, I braved a wet, windy morning to see how my own bins were getting on.

I had stopped using my fruitcage one a few weeks ago and found it measured 8C. But it was 19C in one I had topped up yesterday.

If you checked the temperature at different stages of decomposition, you’d find it was hot at the top and cool at the bottom. Worms are a good barometer for this.

You’ll find them breaking down and enriching material at the bottom and steering clear of the hot top.

Some loll around in the moist lid, but never in the heap. Incidentally, there’s no better way of dealing with raw kitchen waste than using a wormery.

I have one in the workshop and its inhabitants respond well to a regular supply of food and reward me with rich wormcast for my pots.

But what do you do when there’s no more room in the compost bin? Why not fill 2 or 3 plastic bags with the partly rotted compost from the bottom, tie up and place in an out of the way corner?

Composting will continue in the bags and you may have useable stuff by the spring. And there’s space in the bin for more waste.

If you’re emptying a pot, refresh its spent compost rather than chucking it. Put 7-8cm of the compost in a large plastic bag, cover with a thin layer of raw kitchen waste sprinkling some compost activator on top. Cover with more spent compost and repeat till the bag is full. Tie up and leave for a few months, when it’ll be ready to use.

Alternatively, directly enrich part of the garden by trying out the traditional trench composting technique. Dig out a trench to whatever length and width you like, placing the excavated soil to one side.

Tip the contents of a compost caddy into the trench and thinly cover with soil. Repeat this and gradually fill the designated area.

This technique works well in the vegetable patch and is specially useful for late summer crops like runner beans.

Plant of the week

Cyclamen persicum has scented flowers in brilliant shades of pink, red and white and prettily marbled leaves. Best grown in a pot in a very sheltered spot as they are not frost hardy; bring indoors when the weather is cold or very wet.