Composting is a crucial skill for all organic gardeners. If you do not currently compost your own waste materials from your kitchen and garden – now is the time to start! Cold composting is the simplest and easiest form of composting – it simply involves making a heap of green (nitrogen rich) and brown (carbon rich) materials and pretty much letting nature get on with its work. You can learn more about composting elsewhere on this site. In this article, however, we will not look at what you should put on your compost heap – but what you should not. To help you avoid some of the most common pitfalls, here are five things you should keep off your compost heap:
Dog or Cat Droppings
Plenty of pet droppings can make valuable additions to your compost heap, and can be used to enrich the soil in your polytunnel garden. The droppings of dogs, cats and other carnivores, however, should not be used in a cold composting system. The low temperatures in a regular compost heap will not be high enough to kill the parasites and other dangerous micro-organisms in this waste, so it can be dangerous to introduce these where you will be using the compost around edible crops.
If you do wish to compost such material, you must do so separately, in a hot composting system which will kill all the nasties. You could then use the results of this hot composting system around non-edible plants in your garden. (Interestingly, some people actually use the same techniques to compost their own ‘humanure’!)
Meat & Fish
Meat and fish will decompose no problem in a home composting system – the problem is that in a cold composting heap, they can be rather smelly while they do so. Unfortunately, meat and fish scraps can also attract unwanted pests such as rats and mice to your compost heap. For these reasons, it is usually best to avoid putting these things on your cold compost heap and instead composting these using a hot composting system before using the nutrients on your garden.
Tea Bags or Coffee Bags
Many people are surprised to learn that most of the ‘paper’ tea bags or coffee bags on the market contain plastic. Synthetic materials are used to ‘glue’ most of these bags together. If you have an organic garden, you will most definitely want to avoid introducing these synthetic materials to your compost heap. They will not break down and can contain chemicals that you do not want in your polytunnel garden. Check that the bags you use are plastic free, or remove the grounds or leaves from the bags before adding them to the compost heap. You should be sure to add the tea and coffee though – they provide plenty of nutrients that can be very beneficial in your garden.
Glossy, Coated Paper or Card
While some paper, newspaper and card can be added to your compost heap, you should be sure to avoid any paper products that have been coated with plastic or bleached with certain toxins. Bright, glossy paper like that used in most magazines will not decompose properly and can contain chemicals that can be harmful for compost to be used around edible plants. You should also beware of certain non-natural inks, which can also contain toxins that could pose a risk to human health. The horrible little sticky labels often found on fruit and vegetables bought from a supermarket should also be kept off the compost heap. Remove these stickers before you put skins or scraps in the compost.
Ash From a Coal Fire
Finally, while moderate amounts of wood ash can be added to a compost heap, you should avoid adding ash from coal, charcoal briquette or coke fires, as these contain a lot of sulfur, which can make compost too acidic and harm your plants.
Learning what you can and cannot put on your compost heap is one of the first steps in creating a valuable compost to help you maintain the soil in your polytunnel. Any composting tips to share? Let us know in the comments below.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.