When using a home cold composting system most people just add material to the bin as, and when, it becomes available. This is clearly a convenient system as vegetable peelings and other kitchen waste are produced throughout the year, as is a supply of Browns in the form of cardboard and shredded paper.
On allotments the picture is slightly different as some allotment gardeners only seem to grow spring and summer crops and once these have been harvested, and the plot dug over, disappear for the winter months. The plot holder only appears on the allotment at irregular intervals during the winter months to harvest the occasional root crop, Brussels sprout stalk or leek. On such plots, there will only have a very limited amount of vegetable tops or trimmings available during the winter months and the compost bin can be allowed to join its owner in virtual hibernation.
However, other allotment gardeners adopt a more challenging system involving succession planting so that are crops are harvested for most of the year. In these cases at least one allotment compost bin can be insulated and kept operational during the winter months (see winter composting) to deal with the compostable material from these plants as they are harvested.
As this is a composting website, I felt in would be a useful to include those vegetables that can be harvested during each month of the year to give an indication of the possible source of compostable material in the form of tops, tails and other trimmings or plants as they are discarded after cropping. I leave the gardeners to look up the sowing dates necessary to get the steady supply of fresh home grown food across the year.
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. At home, where there is a regular supply of kitchen waste, and if the temperature is about 10°C for most of the time, material can be added to the bin knowing that microbes will spring into action.
Depending where you live some authors suggest starting the bin once the temperature is above zero on most days but in the UK I would suggest waiting a few weeks for it to get a little warmer. My recommended indication of the time to start a new bin is once the grass on the lawn, or allotment paths, has grown enough to need cutting as this will provide a regular source “Greens” to start the bin if there is little in the way of other garden waste available
Even if you are not planning to use a batch or hot composting approach (Composting methods) I would suggest that when starting a new compost bin or heap in the spring, the material is turned, or aerated with an aeration tool, do this 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 and corrugated cardboard.
Reawakening Existing Bins
If you already have a compost bin or heap, it will reactivate naturally, as the temperature rises. The materials that have sat in the bin relatively inactive during the winter will start or recommence decomposing without help from us, although the addition of coffee grounds helps wake up the bins just as it does us..
Adding more natural materials to those left from the previous season give the bin a boost, and the feeding of the bin can be increased as more resources become available (see below) .
As with new heap aeration will speed up the process and as the temperature in the bin increases. (See compost temperature).
Spring is also one a good time of year to harvest compost for use on the garden (Using Compost).
Material for the bin will also be available as a result of the spring tidying of the garden, cutting back and removing dead leaves from perennials that had been left on the plant over winter to provide some frost protection.
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. Spring prunings from blackcurrants, blueberries, gooseberries and autumn fruiting raspberries can be composted after shredding.
April may provide spring cabbages, cauliflower and sprouting broccoli as well as weeds removed when preparing seedbeds. The prunings of plums and cherries might also be available for composting in April.
May should see a rise in temperature helping the compost bin to move into gear, and weeds to multiply providing an addition source of fresh young “green” material for the bin. 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.
Compost can be used as a mulch once the soil has warmed up in mid- to late spring. It should be applied when the soil is moist
Compost can also be used to top dress the lawn in the spring to start the season but do it early so that the lawn will be looking good when you want to use it. The use of compost to make liquid feed is given on a separate page Liquid Feed.
Summer –June, July and August.
The compost heap will be working at its best during the hotter summer months. 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 (Compost Moisture )
If hot composting in a New Zealand bin or Green Johanna layer the your materials you add to the bin. After addding nitrogen rich Green organic matter ovand a layer of browns as this will help reduce the numnber of fruit flies. Water regulaly , during turning the contents to aerate the material is the best time to add water. Remember with the Johanna it is the top kayer that is aerated with a New Zealand bin turn the whole heap.
If rapid or hot composting there may already be the first of this year’s compost ready to harvest. 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 during the summer months.
Compost the 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 pulled up 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 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 ( Composting methods )
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
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 compost bin worthwhile. As I have to two Clumber Spaniels which shed continuously throughout the year my vacuum cleaner provides a constant supply of dog hair.
An established lawn can be fed using an 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.
Autumn – September, October and November.
Autumn is also considered by some as the best time to start composting as the tidying and cleaning up of the garden in readiness for winter provides plenty of material and, hopefully, the bin will have time get into its stride before the worst of the cold weather.
Autumn is also recommended as a good time to apply compost as a mulch it can be applied both to established beds and around specimen plants. Compost can be used as mulch to top dress the lawn in the autumn when people are less likely to spend time in the garden and may not worry about the look of compost on the lawn.
Whether starting a new bin, or operating an existing one, getting it decomposing well throughout the autumn, when the weather is kind, will help to provide a good crop of compost in the spring. If an open pile or New Zealand bin is being used cover it, either with carpet, tarpaulin or a compost duvet, so as to prevent the material becoming water logged and aerate it so as to keep it working for as long as possible.
It is a good idea to increase the surface area of waste added to the bin in the autumn, even if the material added to the bin is not usually shredded for the rest of the year, so as to help speed the composting process. If it is soft material it can be put on the lawn and run over with the lawn mower if a shredder is not available.
There is likely to be a lot of material available at this time of year. If it is not practical to start a second bin, store it in a covered pile. It is important to keep the pile dry, as dry material will heat up in a bin more quickly than wet. Material being saved in the autumn for use as bulking agent in food composting e.g. sawdust or composted wood chip used should also be kept dry. (I keep mine in plastic dustbins)
September is the time to compost the dead (or dying) summer flowers and material from the last of the summer vegetables, including the plants themselves, e.g. beans, globe artichokes, tomatoes and peppers and those cropping during the autumn e.g. marrow squashes, leeks and main crop potatoes.
Continue harvesting comfrey until late September when it should be left uncut for the leaves to die of naturally.
In October, any remaining summer crops can be composted along with potato helms and beetroot tops as they are lifted. Any remaining climbing bean, pea or tomato plants can be chopped into small pieces for composting as the supports are taken down. Discoloured and blotchy leaves are safe to compost as the organisms causing the blotches will be broken down in during the composting process. The roots of plants with soil borne diseases such as brassicas with club-root in and white rot in onions should not be cold composted as the spores will survive.
Squashes, pumpkins can be harvested and the plants chopped and composted. Carved pumpkins can be composted after Halloween Composting Pumpkins
Autumn weeds can be composted if the allotment is to dug, manured and left for the winter.
The tops and trimmers of root vegetables will continue to be available for composting on the allotment and their peelings from the kitchen This is the main time of year for pruning fruit trees and bushes (except cherries and plums) proving shredded material for the compost bin.
There should still plenty of material available to feed the compost heap with more becoming available as plants in the flower bed catch the frost. 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. 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 winter.
Towards the end of the month 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 scrumpled cardboard shredded paper, woodchip or sawdust can be added.
Wormeries should be moved into a shed or outbuilding or if they are to be left outside during the winter the bin should be insulated so that the contents and worms are not frozen, I have round that a triple layer of bubble wrap makes an excellent insulating material which does not absorb water, is clean and easy to reuse. The worms will still need feeding during the winter, although at a reduced rate, so a removable bubble wrap lid should be included.
Bag autumn leaves for leaf mould or as a carbon-rich winter source of Browns for the compost bin on the allotment where cardboard or shredded paper will not be available. The autumn leaves can also be used immediately in the compost bin layering them with grass clippings, kitchen waste and other plant material but remember that the leaves tend to be slow to decompose, so this may not be the method of choice (see Leaf mould). Some leaves can be set aside to add to the compost bin during the winter months to provide a source of Browns when most of the other material being added is kitchen waste.
Winter – December to the end of February
As with every season of the year some sources argue that winter is a good time to start a compost bin. However on this occasion it is suggested that the start of the season is the time to choose because the composting process should be complete when spring arrives. However, as the outside temperature falls the process of decomposition will slow and if below freezing for some time may stop.
If you want your compost heap or bin to stay active during the winter, it will be necessary to insulate the bin (Winter Composting) It is generally recommended that the compost bin is not turned or aerated during the winter months. Concentrate on keeping it warm by the addition of insulations and, even if you are allowing the bin to hibinate over it so as to prevent the contents becoming water logged.
Continue adding material to the bin. Help to generate the heat necessary to keep the composting microbes active by adding more coffee grounds (ask at your local coffee shop- many of the chains are only too happy to give coffee grounds to composters), cow and horse manure helps give the heap a boost and molasses or black treacle (mixed 1:20 with water) can also be added.
If autumn leaves where bagged for making leafmould some of them can now be diverted to the compost bin as an additional source of carbon rich Browns.
Wood ash from the wood burning stove could also be added during the winter to add a different texture to the mix.
The vegetable garden can provide tops and trimmings from celeriac, parsnips, Swedes and turnips will continue through December along with leeks, brassicas.
If winter pruning apple or pear trees shred and compost the pruned wood.
Feeding the bin should continue. In January, vegetable trimmings and peelings that may be available in include winter cabbage, cauliflowers, celeriac, kohl rabbi, leeks, parsnips and Swedes. If grown on an allotment these should be trimmed on site and the leaves added to the allotment compost bin or heap. Check the swedes, chop, and compost any that have grown too big and woody. The stems of brassicas should be chopped into small pieces using a spade or shredded otherwise as they will be very slow to decompose.
Some recommend adding a thin layer of the dried leaves bagged in the autumn as an additional carbon source and of course, wood ash from the wood burning stove can also be composted.