Making the perfect compost heap

Composting is one of the most talked-about activities in the gardening world, but one which few do well.


Adding organic matter to your soil in the form of garden compost improves you soil’s structure and its ability to hang on to water and nutrients for the benefit of your plants.

Most gardeners have a compost heap where waste from the garden is piled up and left to rot. However, this does not always produce good garden compost, perfect for mulching and conditioning your soil. Usually grass clippings are the main component in summer and fallen leaves in autumn and early winter. Both are good ingredients, but only when used in the right way. Fresh, moist grass clippings left alone in a heap soon degenerate into a slimy mass. Dry, fallen leaves take ages to break down, often remaining intact for years, rather than months.

So, what are the secrets of success?

Air and water

The first thing to remember is that successful composting needs both air and water. Wet, green waste, especially grass clippings, has little air space. Therefore it rots anaerobically, without air. This type of composting produces a lot of heat, but it cools down quickly. Dry leaves on the other hand have plenty of air, but insufficient water. Composting is gradual, producing little heat and slow results.

What’s needed is a combination of both.

Green and Brown waste

Green waste includes grass clippings, annual weeds (without seeds!), light shrub clippings, vegetable and fruit peelings, faded flowers and fleshy stems

Brown waste includes fallen leaves, dry stems and woody pruning’s, dry grass, leaves and straw.

By building a heap in layers of each type of waste, adding water if necessary and a light sprinkling of Vitax Compost Maker you encourage aerobic composting which produces good-quality soil-conditioning compost.

Saving those fallen leaves in autumn and winter is a great way of preparing for next spring’s grass cuttings.

Keeping the heat in

As the compost is broken down by aerobic bacteria heat is produced. This accelerates the composting process. The more heat you can keep in the heap, the faster the process and the more likely you are to kill off any weed seeds that have found their way into the heap. Insulating the compost with old carpets is a great way to keep the heat in. Wooden compost containers are also the most efficient when it comes to insulation.

Turning the heap

Expert composters will recommend turning the compost once the first stage of the composting process has taken place. If you have a compartmented composting area with several bins this is easily achieved by just turning the compost from one bin into the next using a fork.

This re-mixes the compost and re-starts the composting process with the material that escaped first time round. If necessary layers of more green waste can be added and additional sprinklings of Vitax Compost Maker. This is also an opportunity to add more water if the compost is dry.

Composting in small gardens

In small gardens moulded plastic compost bins are often the best solution. Compostable material is added at the top and it should be possible to shovel ready-to-use compost from the outlet at the base.

Always site the compost container in a sheltered place where it is not cooled by winds. It is equally important to use a variety of green and brown waste and to add this in layers.

A soil base

It is always best to site any compost container, large of small on a soil base. This allows access for earthworms which are a valuable part of the composting process.

If there is a risk of vermin entering the heap in this way lay chicken wire across the ground before you site your compost container.

How long does it take?

The composting process can take up to twelve months. However, it can be considerably quicker if you insulate the heap well and use material that breaks down quickly. Cutting up your brown waste as you add it to the compost heap really helps. Mowing up fallen leaves chops them and makes them break down more quickly. Vitax Compost Maker contains organic nutrients and accelerates the composting process which can be complete in just six weeks.

Andy McIndoe for Vitax