Compost: The Final Product
Compost should be dark brown with a crumbly texture and pleasant, soil-like smell. The decomposition of bulky organic materials requires oxygen, moisture and the right balance of carbon- and nitrogen-rich waste, which means that careful management is necessary. However, a successful compost pile is easy to achieve.
Different Compost Bin Designs
Your first task is to find a compost bin that suits the size of your garden and the amount of waste to be broken down. It is best to have two bins, to allow the contents of one to be aerated by turning it into a second bin, which means that a new pile can be started in the first. The type of bin you choose depends on appearance, space and cost considerations, but ensure that it has a loose-fitting cover to prevent waterlogging. Place your bin on bare soil, add compostable material and let nature do the rest.
Wooden Bins: Wooden bins look good and can be bought or homemade. Choose a design with removable front slats for easy turning (Image 1).
Plastic Bins: Plastic bins are relatively cheap and simple to install, but their design means that turning the contents can be tricky (Image 2).
Wire Bins: Bins constructed from wire mesh are particularly suitable for composting fallen leaves to make leafmold (Image 3).
What Goes on the Pile?
Almost all plant waste from the garden can be composted, except for diseased material, perennial weeds and meat and cooked waste, which attracts vermin. Nitrogen-rich (green) waste aids decomposition, but this must be balanced with carbon-rich (brown) waste to open up the structure of the pile and allow air to circulate. Aim to add a 50:50 mix of green and brown waste to your pile during the year.
What to Add to the Compost Pile
- Carbon-rich woody prunings and hedge trimmings (which usually need to be shredded), plant stems, fall leaves, shredded newspaper and cardboard.
- Nitrogen-rich grass cuttings, herbaceous plant material, weeds, vegetable plants, fruit and vegetable peels, tea bags, coffee grounds.
Making a Compost Trench
Kitchen waste, such as fruit and vegetable peels, tea bags and eggshells can also be composted in a long trench (Image 1). The trench is best made during the fall, when large areas of soil are often bare and the waste has time to break down before planting begins in spring. Vigorous plants, such as runner beans and squashes, respond particularly well to the high nutrient levels provided by kitchen leftovers.
Dig a trench about 12 inches wide to one spade's depth and fill it with alternate layers of waste and soil. Then add a layer of soil on top (Image 2). Allow at least two months before planting over the trench. As with any composting method, do not include meat or cooked waste because it may attract vermin.
Text copyright 2007 Royal Horticultural Society