Composting is easy in summer. Temperatures are high and there’s an abundance of soft green material that will break down quickly when blended with woody prunings.
By contrast, in winter, the temperature at the core of your heap can drop to the point where decomposition stops altogether.
The rotting process in a well-made heap will generate its own heat. Insulation, such as flattened cardboard, old carpet or polythene sacks filled with straw will help retain this heat. It’s also important to stop the winter heap becoming overly wet, so covering the bin is vital.
The secret to perfect compost is to get the right ingredients well mixed or layered. Follow our tips for success, below.
Keep heat in
Covered bins and heaps allow waste to heat up quickly and compost faster. A lid also keeps out heavy winter rains which can chill or overly wet your compost heap. Although garden waste does eventually compost in a heap, a bin is much more efficient.
Even better, use two bins so one can ‘cook’ while the other fills. Either go for a purpose-built container or make your own using wood, breeze blocks or pallets. Line with flattened cardboard boxes.
Chop and shred
Woody material is best added to the heap in small pieces to provide a greater surface area for organisms to work on, which speeds decomposition and generates heat. More woody waste is cut in winter and can take years to break down unless chopped up.
By hand is slow but you can buy, hire or share a shredder to reduce the cost. Large quantities of leaves are best composted separately in a wire mesh container or plastic sack pierced with holes.
Maintain a balance
Aim for a roughly equal mix of moist and dry materials – usually referred to as ‘greens’ and ‘browns’. Moist, nitrogen-rich greens including lawn mowings, fresh horse manure and green weeds are in short supply in winter, while plentiful brown matter, such as shredded woody stems, leaves and paper can cause the heap to dry out.
Don’t simply dump lots of brown material onto the heap – stockpile it in old compost bags or separate heaps until you have sufficient green material to add in equal quantities.
Turn for speed
Getting air into the heap literally breathes life into it during the winter, boosting populations of organisms so the compost heats up and therefore breaks down more quickly. To turn compost, empty out the bin and refill it, turning the sides towards the middle so it composts evenly.
For ultra-fast compost, collect enough waste to fill a bin in one go, then empty and turn it as often as you can manage. If shifting compost by hand sounds too heavy, invest in a tumbling compost bin.
Worms and other organisms will be more active if your bin is warm in winter, ‘cooking’ your compost quicker. This is especially important if you are using a wormery. Cover your bin with flattened cardboard boxes, old carpet or large polythene sacks filled with broken-up polystyrene or straw.