Expert advice from 'Gardening Which?' by Rosemary Ward
A glance around any allotment tells you that gardeners are natural recyclers. Coldframes built from old windows; bean supports from discarded water pipes and tennis nets; pots, labels and mini-cloches fashioned from plastic food containers - this is invention born of necessity. Now the larger imperative of protecting the environment is driving us in the same direction.
Reducing demand for new products saves precious raw materials and energy, while making good use of waste reduces the demand for expensive, ugly and possibly hazardous landfill or incineration sites. Reducing the waste mountain is something everyone can get involved in, and where better to start than the garden? Here, with a little encouragement, nature will recycle all our organic waste into crumbly compost - the best soil improver there is - for nothing.
* Encourage the natural bacteria and fungi responsible for composting by providing air, water, warmth and a mix of material to work on. A compost bin is not essential but looks tidier and should help provide the right conditions (see below).
* Use a mixture of waste matter. Soft, green stuff such as grass clippings, vegetable peelings and young weeds contains lots of moisture and decomposes quickly but tends to collapse into a soggy mass which excludes air. Tougher brown materials such as hedge prunings, remains of vegetable crops and fibrous stems rot more slowly and tend to dry out, but allow in lots of air. A mixture creates a perfect balance.
* Add to your bin: fruit and vegetable waste, tea bags and coffee grounds, shrub prunings (preferably chopped up or shredded first), grass clippings, farmyard and stable manure, plant remains after cropping, autumn leaves and anything else of plant or animal origin which is not in the don't add list (below). If you throw in end of season bedding and container plants beware of those infested with vine weevil or notorious self-seeders such as forget-me-nots.
* Don't add: meat, fish or cooked food which can attract rats, perennial wood roots or seedheads, diseased plants, man-made materials such as plastic which will not rot, dog and cat droppings which could contain parasites, soot and vacuum cleaner dust which may contain heavy metals, thorny prunings, glossy paper which rots very slowly.
* It's OK to add small amounts of paper and cardboard - best scrunched up, natural fibres such as cotton and wool, sawdust and wood shavings, though they are slow to compost.
* If the compost is not rotting properly, empty out the the bin. Mix up the inside and outside layers. If it is too dry, add water. If too wet, add dry material such as straw, pillow feathers or torn and scrunched up newspaper. If you have the energy, turning the compost frequently does speed up the rotting process.
Making a compost bin
Generally the bigger the better as large volumes heat up better - up to one metre cubed if you have enough material to fill it within a few months. The ideal is three bins - one to be filling, one to be composting and one to use. If you build your own you can easily make three bays of the size to suit your garden - using recycled material, of course. Wooden pallets are good - ideally treated against rot or they will be short-lived.
Leave gaps between the wooden slats - the wetter your compost materials, the larger the gaps need to be. Alternatively use bricks or breezeblocks, leaving ventilation gaps. A lid is useful to keep out torrential rain, but also helps to prevent the heap from drying out. A layer of old carpet or similar on top of the compost itself will keep in warmth.
It's best if the bin stands on soil, so that excess moisture can drain away and soil creatures have easy access.
Other recycling ideas
* Shred woody waste. If dealing with woody cuttings or small branches don't burn or dump them. Instead, use a shredder to turn this waste into weed suppressing mulch. The mulch will also help stop the soil drying out.
* Reuse pots. Plastic pots and trays can be washed and reused indefinitely. Save money by improvising with food and drink containers too. A recent high court decision to class many plastic pots as packaging should mean more pot recycling schemes are developed - a good project to start in a school.
* Conserve water. Recent bouts of wet weather aren't typical (mid-Kent has reported water shortages this summer). Fit water butts to collect rainwater and reuse "grey water" from washing and bathing. Water early in the morning or late in the evening so you lose less water through evaporation. Water directly where it is needed - don't use sprinklers, or watering cans with a rose, which waste a lot of water.
* Use recycled materials. Everything from potting compost to garden furniture can be made from recycled materials, which saves energy, natural resources and your money. Think about how you could reuse waste materials such as using broken up polystyrene packaging in the bottom of deep pots as an alternative to crocks.
* Do a rubbish bin audit. See how much you could reduce the contents of your household waste by reusing or recycling materials - another possible project for your pupils.