The National Allotment Society - National Society of Allotment and Leisure Gardeners Ltd

The Composting Year

Summer –June, July and August.

The compost heap will be working at its best during the hotter summer months as the warmth and rain increase the activity of the composting micro-organisms. A cold system will be at its maximum rate of decomposition, helped by the regular addition of feedstock and aeration. As temperatures increase plastic bins and covered heaps may dry out so it is important to monitor the situation and water if necessary. If hot composting requiring the addition of composting material in batches sufficient to fill the bin it helps to layer the materials alternating nitrogen rich Green organic matter a with a layer of Browns. The bin or heap should be watered when adding the layers and during dry periods regularly moisten when turning the contents to aerate and maintain the temperature. The objective is to hold the material at a temperature at 50C plus for as long as possible. Ensuring that there is a layer of Browns on top of the compost will help reduce the number of fruit flies

If hot composting using a Green Johanna or a Hotbin only the top layers will need aerating not the whole pile as is necessary when batch composting with a New Zealand bin.

If rapid or hot composting techniques are being used producing compost in only a few weeks, the first of this year’s compost will be ready to ready to harvest during the early summer period. This should be covered and stored to allow it to mature in a maturation bin. Providing sufficient organic waste is available, it should be possible when using hot composting techniques, or a tumbler bin, to produce several batches of compost over the summer months. Compost any remaining leaves and flower heads from spring flowers as they go over. Weeds will be growing well and where as non-seeding annuals can be added directly to the bin perennials should be drowned or dried out before being added to the composting mix.

The vegetable garden should be producing a bumper crop of vegetation for the compost bin in June. These might include the tops of new season early potatoes and beetroot, which can be added to the allotment bin. The kitchen compost bin will benefit from the pods of peas and broad beans followed by French and runner beans in July.

July will also provide leaves removed to provide access to courgettes, carrot, beetroot, and more potato tops as well as trimmings for summer salads. There may also be some apples and pears if there is a heavy crop which thinning out.

August should see the last of the early planted broad beans and enabling the bean plants to be pulled up, chopped and added to the compost bin. It also sees the start of the sweet corn crop. Any stalks pulled up accidentally during harvesting should be chopped or shredded before composting. The sweet corn cobs should be chopped and composted once the corn has been removed/eaten.

During the summer, if you have a lawn, there should be a good supply of grass clippings. When adding these to the bin be sure to add sufficient browns to prevent them forming a black, smelly, anaerobic mat inside the bin. If you find that you have more than you can compost in your bin, consider Grass Boarding layers of grass and cardboard.

As a composting bonus, there will be leftover salad and other food from barbecues as well as the ash from lump wood charcoal (not briquettes)

Continue harvesting comfrey every two weeks to make Comfrey Tea of as an activator in the compost bin.

Many composting sources say that hair can be composted but it never seems an effective use of time to collect a few strands of human hair from the comb or brush. Nevertheless, summer can see dogs shedding their winter coats and even if the hair is not saved from grooming there is likely to be sufficient collected when vacuuming to make a trip to the allotment compost bin worthwhile.

An established lawn can be fed using a 50:50 mix of sharp sand and sieved compost o form a layer about 2.5 cm thick during the summer. This may look unsightly initially but will soon disappear. Alternative compost tea can be used to feed the lawn.

This is the main time of year for pruning fruit trees and bushes (except cherries and plums) providing shredded “Brown” material for the compost bin.
If the compost heap starts overflowing either start a new bin or store the material until the heap subsides and the waste can be added. Stored green material may start to decompose but it can still be added to the bin when space becomes available. It is helpful to turn the compost heap, or bin, to mix the new material and aerate it to encourage the composting processes before the onset of the autumn.

Towards the end of the summer it is advisable to check the consistency and moisture level of the contents. If the material is too dry more greens can be added e.g. nettles and annual weeds along with water or the sludge from compost tea. If too wet crumpled cardboard, shredded paper, woodchip or sawdust can be added.

Harvesting the Compost
Finished compost is a rich dark brown colour, has an earthy smell and crumbles in the hand. If using hot composting techniques, the process started in the early summer should be ready in 3-6 weeks and while the compost produced by cold composting is normally harvested in the autumn it is worth checking towards the end of the summer whether the process is complete.

Details of liquid feeds and home-made potting mixes and other composting information can be found at www.carryoncomposting

Spring, March to May 31

Starting a New Bin

 Any time of year is a good time to start composting but each season offers its own advantages.

Starting a compost bin in spring offers the opportunity to take advantage of the warmer weather and the increasing activity of the composting microorganisms and compost creatures. However, you will need material to start and feed your bin. Once the   temperature is about 10°C for most of the time, material can be added to the bin knowing that the composting microbes will be active.  An alternative method of determining when to start is to wait until the grass on the allotment paths has grown enough to need cutting. Conveniently this will provide a regular source “Greens” to start the bin if there is little in the way of other plant waste available

Even if you are not planning to use a batch or hot composting technique when starting a new compost bin or heap in the spring, it speeds the process if the material is turned, or aerated with an aeration tool, regularly for the first few weeks to allow air into its deeper pockets. This is particularly the case if grass is being composted as it not only needs aerating but also will require mixing with a plentiful supply of Browns e.g. shredded paper, corrugated cardboard or leaves save from the autumn.

Reawakening Existing Bins

An existing compost bin, or heap, will reactivate naturally as the temperature rises. The materials that have overwintered will  recommence decomposing as the temperature rises, although the addition of coffee grounds helps wake up the bins just as it does us.

The last remaining winter vegetables can be harvested, and their tops and trimmings added to the compost bin in March, these might include Brussels sprouts, celeriac, parsnips and swedes.  The Spring pruning from blackcurrants, blueberries, gooseberries and autumn fruiting raspberries can be also composted after shredding or cutting into short lengths. As with new heap aeration will speed up the process and as the temperature in the bin increases.

April may provide spring cabbages, cauliflower and sprouting broccoli as well as weeds removed when preparing seedbeds. The plums and cherries pruned in April might also be available for composting.

May should see a rise in temperature helping the compost bin to move into gear helped by the addition of annual weeds a source of fresh young “green” material. The vegetable harvest may include tops turnips and trimmings from fresh garlic.

If growing Comfrey   the first cutting can take place when the foliage is 12 to 18 inches tall. Cut about two inches above the ground.  It should be possible to continue cutting the comfrey every 10 to 30 days through the summer months.

Spring is also a good time of year to harvest compost for use on the garden. Compost, applied when the soil is moist, can be used as a mulch once the soil has warmed up in mid- to late spring. Over wintered compost can also be used to make compost tea, a useful liquid feed. It can also be used to make home made sowing and potting compost.

Details of liquid feeds and home-made potting mixes and other composting information can be found at www.carryoncomposting