‘You know you are a gardener, if you find compost a fascinating subject’.
– author unknown.
Over the last few years we have all got used to the idea of recycling waste household products. Most local authorities now have a schedule for collecting recyclable materials on a regular basis, and separately from the normal collection. Polythene bags are provided for this by our council, and in our household the day for collection is referred to as ‘Green Bag Day’. However the council decrees that only certain materials are fit for recycling. This means an awful lot of waste is still tipped, probably in landfill sites, or out to sea.
Here is where good gardeners can play a small part in the recycling process, help the environment, and do a power of good to the garden by composting a lot of waste that is normally consigned to the dustbin.
So what is all this compost or composting about?
I once read an article on composting that went something like this… ‘The ideal ratio of carbon to nitrogen in a compost pile is about 30:1 .’. Calculate your pile’s Total Carbon Value by multiplying the percent carbon of each ingredient by the number of parts (by weight) of that ingredient and then adding up the carbon totals for all the ingredients. Make the same calculation for the nitrogen. Divide the carbon by the nitrogen to get the C:N ratio. It should be between 25 and 35. If the ratio is higher or lower than that, adjust the proportions of ingredients to bring it into the range of 25 to 35 parts carbon for each one part nitrogen ‘
What were they trying to tell me !?
Well I don’t know my TCV’s from my C: N ratios, but I do know that if you put a load of waste organic material in a heap it will eventually rot. Put quite simply composting is a means of returning to the soil waste organic matter by the natural process of rotting.
Not exactly rocket science is it? Let’s do it.
If you don’t mind a bit of a mess, you can just pile up, in a heap, any organic material from the garden and the kitchen, and leave it to do it’s own thing.
But it’s nice to keep the garden tidy, so I prefer a method using three enclosed compost bins, two will do, and they don’t have to be enclosed. This is simply to enable us to turn the compost over from one bin to another, which needs to be done every month or so, to mix and aerate the contents.
My bins are made of old timber, but plastic compost bins will do the job, or wire netting around four posts.
I reckon to produce good crumbly compost in six months to two years depending on the mix of materials and the weather. In winter the process is very slow and sometimes comes to a complete standstill, because one of the secrets of composting is heat.
There are four main things to consider for successful composting.
▪ A balanced mix of materials.
▪ Regular turning.
A balanced mix with regular turning will aerate the compost heap and produce the heat that drives the rotting process.
Anything organic can be chucked into the compost bin. All kitchen scraps, potato peelings, any vegetable matter, tea bags (old ones of course, that have been on the piece of string too long!) coffee grounds, even old clothes. Soft cuttings and prunings, most garden waste that isn’t too ‘woody’, unless you can shred them, straw, leaves and old spent compost from pots and containers, and crumpled cardboard and newspaper.
Getting a balanced mix is difficult, because you are dependent on what is available for composting at any particular time. This is why regular turning of the pile is essential. Try to get a good mix by layering materials. That is, alternate six-inch layers of grass cuttings, or other garden waste, with six-inch layers of kitchen scraps and / or shredded newspaper and leaves.
There are a number of things that can be done to speed up the rotting process if you are in a hurry. Proprietary accelerators can be bought from garden centres, but just as effective, for the gentlemen, is to nip behind the garden shed with an old tin can, pee in it and add the contents to the compost heap! I kid you not. Nettles are also good accelerators.
I also add worms to the pile; they help to make good compost. Whenever manure is available a shovel full mixed in helps raise the temperature.
Keep a lid or cover on your pile, a compost heap needs to be moist, but not sodden.
Finished compost takes up less than half the space occupied by the original pile. When the individual materials can no longer be identified and the pile resembles dark rich soil, the process is complete. It should smell sweet, woodsy, and earthy. It will crumble through your fingers.
The factors noted in the suggestions above will determine how long the process takes. Everything matters — how often the pile is turned, what materials went into the pile, the condition of the materials, moisture, adequate air, presence of insulation around the pile, size of the pile, etc.
If you add materials as you get them, you will find that after 6 months to two years, the inside and bottom of the pile, the matter you added first, has become compost. You may remove this from the bottom of the pile and use it. Return the rest of the materials to the bin or pile location to continue decomposing.
Finally, a few don’ts. Don’t add meat scraps, which may attract vermin. Don’t add pernicious rooted perennial weeds and plants such as Dandelion or Bindweed to your compost. They will persist! Avoid adding any diseased prunings.
And a word of warning. Be careful when you turn your compost heap in summer. I disturbed a wasp’s nest last year, and boy were they angry!