Making Your Own Garden Compost
You can make your own garden compost using a range of different containers, such as plastic bins, wooden boxes or slatted boards (read on to find out how to make a wooden compost bin ...)
The Container
Any container for composting should have a capacity of at least 1 cubic metre (1 cubic yard), a lid to conserve heat and easy access to the compost by slats or panels. Plastic bins are often more effective than wooden or metal versions as they conserve moisture, thus reducing the need for watering. Avoid mesh bins or models with large gaps between the slats, as these allow the generated heat to escape, slowing down the rotting process.
If you have a container that is open at the bottom, make sure that you stand it on soil rather than concrete.
Adding the Material
Start by spreading a layer of dry twiggy material in a 1 m (3 ft) space on the ground, or in the bottom of a compost bin. Build up the heap in 15 cm (6 in) layers, varying the type of material. To make sure that your heap will rot down quickly, you will need to include a mixture of green nitrogen-rich waste (such as grass clippings) and brown carbon-rich waste (such as bark and shredded paper). This should roughly be in the ratio of 1:2. Ingredient suggestions include:
- Kitchen waste such as tea leaves, coffee grounds, vegetable peelings and banana skins
- Young annual weeds
- Grass clippings
- Hedge trimmings
- Discarded bedding plants
- Tree, shrub or rose prunings
- Sawdust from small animal cages
- Cardboard and newspaper
Try to avoid building up thick layers of grass clippings as this will inhibit air movement and turn the heap into a smelly, slimy mess. If you have a large amount of grass to compost, add it to the heap in layers, with sheets of newspaper or junk mail (do not use glossy paper such as magazines) in between. Turn the heap each time you add more clippings to introduce more air into it.
Prunings from woody stems may be used; these will rot down much more quickly if they are cut into small pieces. Use a shredder if you have a large number of shrubs or hedges; a pair of secateurs will be quite adequate for smaller amounts.
Avoid using leaves as they contain a woody tissue that will slow the composting process down. Compost them separately to make leaf-mould.
If the heap begins to smell of rotten eggs, this indicates that it lacks air, whilst a smell of ammonia means that the compost is too rich in nitrogen.
For sucessful composting, avoid using the following materials:
* Diseased plant material
* Perennial weeds such as dandelions or bindweed
* Weeds that have gone to seed
* Used cat litter
* Cooked food - this may attract rats or foxes
Compost Temperature
A compost heap may be hot or cool; a hot heap is built in one go using a large amount of material, whilst a cool one is made by adding small amounts of material over several months. Both methods will create good quality compost, although the cool heap will take longer to do so. The composting process will take place much more rapidly when the weather is warm and a cool heap started in the spring should produce some usable material by the autumn. Turning the heap regularly (every 2-3 weeks) will speed up the process and ensures that the material breaks down completely.
If your compost area does not have a lid, cover the top of the heap with a piece of punctured black plastic or old piece of carpet secured with some large stones or bricks. This will help to conserve heat.
Compost Additives
To kick-start the composting process you may want to consider adding some nitrogen, which will stimulate bacterial activity. Nitrogen may be added as a proprietary compost activator, artificial fertilizer or preferably, as manure, which has the added benefit of containing high levels of soil organisms. Add the nitrogen to each 15 cm (6 in) layer of new material.
If you have a large amount of grass clippings, you may find that you do not need to add a special activator as grass is already high in nitrogen.
Using Garden Compost
After about 3-6 months, the bulky heap of garden and kitchen waste should have rotten down to a dark, crumbly, sweet-smelling material. Use this compost as a soil conditioner to dig into new beds or as a mulch around existing plants. Any material that has not rotted may be re-composted.
At the end of the growing season, recycle any used compost by emptying out your pots and planters and shred in any old plants.
Why not set up 2 or 3 compost bins? This will mean that you'll always have some compost ready and some in the making.