Home Composting: Everything You Need to Know
We may be pioneers of fair trade and the experts in sourcing eco-friendly, future proof, compostable packaging for our products, but when it comes to the nitty gritty of actual home composting, we look to the specialists for advice.
This is why we’ve asked our friends at the Royal Horticultural Society, the world's leading gardening charity - and not just anyone, but their Chief Horticulturalist, Guy Barter - for their expert guidance on how to home compost.
Compost Bin and Site: What Exactly Do You Need?
Choosing where to house your compost is critical. We recommend positioning in shade or semi-shade. You need to make sure that the site is not subjected to extremes of temperature and moisture. This is because the micro-organisms that convert your waste into the rich, fertile compost work best when their conditions are stable and constant. Compost bins which retain some warmth and moisture make better compost, quicker.
An earth base is best, as this allows drainage and access to soil organisms. If this is not possible in your garden, simply add a spadeful of soil to the compost bin before you begin.
Don’t presume that you have to pay a fortune to get the very best compost bins, as any compost bin on the market should produce good compost, as long as they are able to:
- Retain some warmth
- Allow drainage
- Exclude rain
- Let air in
Compost bins less than one cubic metre in size are much less effective than larger ones, so if you have room for it, the bigger, the better! Note: if you have a smaller garden or no garden at all, you can still home compost – read on for Chief Horticulturalist, Guy Barter’s top tips.
What Should I Compost?
Getting the balance right is key to producing great compost. Ideally, between 25-50% soft green materials (e.g. grass cuttings or vegetable/fruit kitchen waste) should be used on your compost heap. This will feed the micro-organisms and allow them to do their magic.
The remainder should be woody, brown material (e.g. hedge trimmings – ideally shredded, wood chippings, paper/cardboard – ideally shredded, straw or dead leaves).
Turning Your Compost Heap
To make compost, you need to add air – which is why it is essential to turn your heap approximately once a month. Remember to keep the heap moist in dry weather – turning will give you an opportunity to assess the moisture level.
Compost can take anywhere between six months to a year to be fully ready to use. You’ll know it’s matured enough when it’s dark brown with a crumbly, soil-like texture and a smell resembling damp woodland.
Don’t worry if not all of your compost has matured at the same pace – this is normal. Any un-rotted material can be added to your next batch of composting materials, and so your self-sufficient home composting cycle continues!
Why Not Try Bokashi?
A Bokashi Kit is a fast and easy way to recycle your food waste into a nutrient rich fertiliser and liquid feed for your garden. It can be kept indoors or out and whenever you have leftovers you add them to your Bokashi bucket along with a handful of Bokashi bran. Bokashi is a Japanese word for fermenting, and this is exactly what happens. The Bokashi bran soaks up the excess liquid from the waste it activates and “pickles” your waste. The double unit kit enables a good sized household to complete eliminate their kitchen waste. All types of food scraps can be dealt with by Bokashi. This includes fruit, vegetables, dairy, coffee, cut flowers, teabags, meat, fish and more. The whole process of fermentation is actually anaerobic so not officially “composting” but it does stop odour and rotting whilst processing the waste. This means you end up with a very valuable end product packed with microbes, nutrients and friendly bacteria to benefit your soil without smell and hassle.
We spoke to RHS Chief Horticulturist, Guy Barter, about all things compost...
What is the difference between the compost we can buy in the shops, and the compost we can make at home ourselves?
It depends on what you mean by compost. There are potting composts used to grow plants in pots. Although these can be home-made, it is usually best to buy readymade ones, ideally peat-free, as these will be formulated to meet plant needs.
Then there is compost used for improving the soil. These are often too rich for potted plants but much better than potting compost when it comes to soil improvement. They are usually made from industrially composted landscape and garden waste and will be effective in soil improvement. In essence, these are similar to home-made garden compost but usually finer and crumblier as they are mechanically shredded, sieved and turned. They are no better for soil and plants than homemade compost and obviously cost more than home compost.
If someone has a very small garden, or no garden at all, can they still home compost? If so, how would you suggest they went about this?
Small scale composting apparatus such as hot boxes, wormeries and Bokashi kits can be very effective in a small space and are largely free of odour and mess.
What sorts of things should we be putting into our compost bins? And importantly, what things should we leave out?
Any soft garden waste and uncooked vegetable or fruit wastes from the kitchen ideally mixed 50:50 with strawy material, including scrunched up newspaper and torn cardboard can be composted. Rhubarb leaves and citrus waste will compost well enough despite common contrary advice.
Lawn mowings set in a soggy mass won’t rot down unless mixed with a great deal of strawy material. Frequent mowing so the small clippings fall back into the grass can avoid the problem of dealing with lawn mowings.
Woody sticks and logs have to be shredded if they are to be composted but can be cut up small and made into log and stick piles to support wildlife, rather than taken to the tip.
Cooked food and any meat or fish will encourage rats and should be disposed of via the municipal food waste collection, destined for energy production in industrial anaerobic digesters.
Weed seeds won’t be destroyed in most garden compost bins, so mature weeds should be destroyed. The same goes for plant material infested with pests and diseases.
Can we continue to home compost all year round?
Composting is a year-round activity but will be much slower in the colder seasons. Good compost in gardens typically takes six months to form. Three months is feasible in summer or an insulated hotbox type composter, if the bin is filled in one go with the right mixture of ingredients and if it turned (the bin dug out and refilled). In dry summers an occasional bucket of water may be required, as dry ingredients won’t rot well.
How important do you personally believe it is to home compost?
By home composting, you save on fertiliser and soil improvers such as manures. Fossil fuel use is reduced too by not taking wastes to the dump or consigning them to green waste collection services.
Compost making encourages many beneficial insects which also support garden wildlife.
The only downside to home composting is if the contents get too wet, then the potent greenhouse gas, methane, is released. To avoid this, turn wet compost and add more dry matter such as newspaper.
Now that you've learnt all the tips and tricks from the experts, whether you have a small, large garden or non-existent outdoor space, why not start producing homemade compost and do your bit for the environment? Your healthy soil will thank you!
It's amazing what you can do with waste, isn't it?