Stoep Harvest part 3: Making compost

This month on Stoep Harvest, we look at composting, an essential part of enriching the soil. We focus on two different ways of going about it. As promised, we also describe the ‘chicken tractor’ an ingenious contraption that does all the hard work in preparing your garden! If you are already a compost fundi, come back next month for summer planting tips.

Composting is the ideal winter activity. While the garden is resting, you can be busy preparing fresh nutrients, a concoction of vitality to add to the garden during the growing season. I like to add compost in two different ways: firstly, with new gardens I dig in a lot of compost before planting. As we saw in the last article, this improves the consistency of both clay and sandy soil types. Secondly, I add compost around the plants by placing it on the top of the garden throughout the growing season. This acts as an insulating mulch and the nutrients seep into the soil and feed the plants.

My favourite way to think about composting is to see it as cooking a meal for the garden. You will need to prepare the ‘ingredients’ and then put them in the correct container and let them ‘cook’.

There are two main types of bacteria that do the ‘cooking’ and these form the two methods of composting:

Aerobic composting

Aerobic simply means that the bacteria depend on oxygen. They are rapid breeders and rapid eaters of organic matter. Aerobic composting is the quicker option and the method I recommend. It is also more labour intensive.

Anaerobic bacteria on the other hand, do not require oxygen. They break down the matter very slowly. Anaerobic or ‘cold’ composting takes a much longer time. It is the easier option: involving little work, simply piling the organic waste in a big heap and leaving it for many months. Aerobic composting, by contrast, can produce quality compost in as little time as twelve weeks.

Here’s a step by step guide for aerobic composting. First, a loose structure or ‘pot’ is required. I have used four pallets tied together at the corners. It is critical that the container allows air to reach the compost. The pot should be placed on loosened bare soil in a shady area.

Ingredients for Cooking Compost

• Wet and green (fresh cuttings/leaves, fruit and veg peels)
• Dry and brown (dry leaves, shredded newspaper and cardboard)
• Manure (optional, although critical for rapid composting)
• Bone meal (optional, stimulates root growth)
• Sticks and small branches
• Do not add: any seeds, meat scraps, or anything rotten.

Instructions

• Place the sticks and small branches at the bottom.
• Layer roughly equal quantities of the wet greens and dry browns. In each layer scatter manure and a little bone meal.
• Add enough water so that each layer is damp.
• Repeat this process with another series of layers, filling the pot as high as possible.
• Finally, cover the pot with a lid such as a pallet or an old piece of carpet. This keeps the compost dark, encouraging the activity of bacteria and also limits evaporation.
• Leave to stand for two weeks.
• After two weeks, remove the lid, untie the corners of the pot, and rebuild the structure adjacent to the original pile. Then start transferring the material into the new pot. This is critical for the breakdown of the organic matter as it exposes the pile to more oxygen.
• Every two weeks repeat this process. After twelve weeks, your compost should be ready for application!

August planting table

• Western and Southern Cape: beetroot, cabbage, carrot, eggplant, lettuce, peas, peppers, potatoes, radish, swiss chard, tomato, and turnip.
• Inland: beetroot, cabbage, carrot, eggplant, leeks, lettuce, peas, peppers, potatoes, swiss chard, and turnip.
• Coastal KZN: bush & pole beans, cabbage, carrot, cucumber, eggplant, lettuce, peppers, radish, squash, spinach, and sweetcorn.

Happy planting! Future topics will include organic pest control, mulching, and companion planting. The author is available for your suggestions and requests for other topics, contact details below.

By Sam Adams

Sam runs Living Green, an organic food gardening company in Cape Town.