Composting through the seasons: spring, summer, autumn and composting in winter

Print

A compost bin doesn't work at the same pace in July as it does in January. When it's warm, the micro-organisms work quickly and you can practically watch the compost progress; when it's cold, everything slows down, sometimes to the point where it seems to stop altogether. Nothing to worry about: you simply need to adapt a few habits to each season.

Here's what to do, and what not to do, throughout the year to keep your compost active twelve months a year.

Spring: restart, empty, get started

As the milder weather returns, activity in the compost bin picks up again. It's the busiest season and, along with autumn, one of the best times to start a new compost bin.

• Get the compost going again with a thorough mix: it puts air back into material compacted over the winter and blends in the additions that have built up on the surface.
• Check the moisture with the squeeze test. After a rainy winter, compost is often too wet: add dry browns.
• Harvest the mature compost from the bottom of the bin to make room. Spring is the right time to spread it between the rows in the vegetable garden, before mulching, or on the lawn and around perennials.
• Take care with the first grass cuttings, which are very plentiful: never in a thick layer, always mixed with dry material.

If you're starting your first compost bin, our guide Starting your compost bin step by step will take you through it stage by stage.

Summer: watch out for dryness

Heat speeds up decomposition: this is the season when compost progresses fastest. But there's a downside: drying out. Dry compost stops dead, because the micro-organisms need water to live.

• Do the squeeze test every week and water if no droplets appear, ideally with rainwater, mixing as you go to spread it evenly.
• Keep the lid closed and, if possible, place the compost bin in partial shade rather than full sun.
• Cover sweet fruit (melon, peaches, plums) with brown material so as not to attract fruit flies.
• Beware of a lack of browns: in summer, we add lots of greens (grass cuttings, fruit peelings) and little dry material. Dip into your store of leaves or shredded material.

Willy's tip

A watering can of rainwater kept next to the compost bin, ready to use, makes it second nature: every time you empty your kitchen caddy, take a quick look, do a quick squeeze, and add a little water if needed.

Autumn: stock up on leaves

Autumn is the season for gathering large amounts of brown material. The fallen leaves that come down in abundance are a valuable resource: they will provide dry material all year round.

• Build up your store: keep several bags of fallen leaves somewhere dry, or pile them up in a corner of the garden. Run over with the lawnmower, they take up less space and break down faster.
• Don't put them all in at once: add them to the compost bin gradually, in step with your kitchen waste.
• Spread mature compost on the surface in the vegetable garden and around shrubs, lightly working it in: autumn or late winter are both good times for this.
• It's also a good season to start a compost bin, with all that dry material available.

If you have lots of leaves, also consider leaf mould, a different product from compost and much prized for sowing seeds: we explain it in our guide Leaf mould.

Winter: keep adding, don't turn

In winter, activity slows down considerably: the cold holds back the micro-organisms, and a household compost bin, which doesn't heat up much at the best of times, loses its warmth even more easily. Does that mean you should stop? No.

• Keep adding your kitchen waste, mixing it with brown material. Keep to a mix of roughly half greens, half browns, adding a little more brown in winter, as less moisture evaporates.
• Turn as little as possible: every turn lets heat escape and slows decomposition even further. A light mix on the surface is enough.
• Don't worry if the level rises: waste builds up over the winter and will be broken down quickly as soon as the fine weather returns.

Opinions differ on this point: some guides advise the opposite, to keep aerating in winter. Our view: in a bin, a little surface mixing when you add material is enough to prevent compaction, without trying to turn the whole volume.

Did you know?

In a well-filled bin, the heart of the compost often stays warmer than the outside air, even in winter, because decomposition gives off a little heat. That's why we avoid turning everything over: it would scatter this precious store of warmth.

Insulating and protecting from rain

Winter's two enemies are cold and excess water. A few simple precautions:

• A lid for bins, or thick cardboard or a tarpaulin for an open heap: compost soaked by winter rain becomes compacted, lacks air and smells unpleasant in spring.
• Insulation for exposed heaps and bins: surround the sides with straw bales or bags of dry leaves.
• A spot sheltered from the wind, ideally somewhere that catches the low winter sun.

A wooden compost bin such as the Compostys Wooden Compost Bin retains heat a little better than a thin plastic bin, as wood is a natural insulator. Tumbler composters, on the other hand, are more "summer workers": poorly insulated and raised off the ground, they don't heat up well in cold weather, and compost progresses very slowly in them during winter.

The compost bin calendar

• March to May: a thorough mix to restart, harvesting mature compost, spreading it on the vegetable garden and lawn, starting a new compost bin.
• June to August: weekly squeeze test, watering if needed, lid closed, sweet fruit covered with browns, monthly mix.
• September to November: store of fallen leaves, autumn spreading, possible start of a new bin, last thorough mix before the cold.
• December to February: continued additions with a little more brown, no turning, lid and insulation, patience.

For mixing during the warmer months, an aerator such as the Brass'Compost saves you emptying the bin. We set out how often to do it depending on your equipment in our guide Moisture and aeration.

Your wormery, for its part, is far more sensitive to extreme temperatures than a garden compost bin, as worms cannot survive frost: see our guide How to protect your wormery from cold and heat.

In summary

In spring, restart, harvest and spread. In summer, keep an eye on moisture and water. In autumn, stock up on fallen leaves for the whole year. In winter, keep adding your waste with a little more brown, cover, insulate and avoid turning. Compost slows down in the cold, but it never really stops: it bounces back with renewed vigour as soon as the first fine days arrive.

Related products

Best Seller

Bokashi Confort Composter

14-litre capacity, available individually or as a set of 2

£34.06 €40.83

Maze 180L Double Chamber Rotating Composter

Effortless outdoor composting

£124.43 €149.17

Compostys wooden composter | 305 litres

PEFC-certified spruce wood

£96.62 €115.83

Pre-order

245L Maze Rotating Composter with Double Chambers

Effortless outdoor composting

£173.09 €207.50

Other topics in the guide

Vermicomposting30 sheets →Bokashi24 sheets →EM micro-organisms26 sheets →