Compost is the foundation to a thriving vegetable garden. In fact, compost heaps are nothing short of horticultural alchemy, turning garden waste and kitchen scraps into nutrient-rich goodness.
If you’re not yet composting, now’s as good a time as any to get started. If you are, then perhaps there’s room for improvement. There’s a lot of advice dispensed on the best ways to do it, but really composting doesn’t need to be that complicated. So stick around as we go back to basics with our guide to making beautiful, earthy compost for free – quickly and efficiently.
Your Composting Setup
For smaller gardens a simple enclosed compost bin does the job. Compost bins with thicker, insulating sides will help to trap warmth and speed up the decomposition process, while tumbling composters may be suitable for larger gardens where a lot of material is generated in one go.
Simple uncontained compost heaps work just as well, however. Larger heaps are more efficient because the centre of the compost is better insulated from the cold.
Enclosing heaps with sides made from old pallets or other repurposed wood is a great way to keep things contained and a little better insulated. One compost heap is great, but if you have the space for two or more heaps, ideally next to each other, then this can make the whole process even easier – more on why later on.
How to Compost
The ideal compost heap has a mixture of fresh ‘greens’ and drier, more woody or fibrous ‘browns’. Greens include grass clippings, weeds, kitchen scraps and most spent crops. Browns include woody prunings, tougher crop residues like tomato stems or corn stalks, fallen leaves, as well as shredded paper and cardboard.
In an ideal world you should aim for a ratio of around two-thirds browns to one-third greens. In reality it’s hard to achieve this precise mix, so don’t fret about it! Better to add things to your heap as you have them, keeping that ideal mix in the back of your mind.
Add ingredients as they’re generated. If they are dry, moisten them as you add them to kickstart the process. Cut up bulkier materials to increase their surface area, which will also help to speed up decomposition. A shredder will make short work of woodier prunings. Cardboard is a great way to add in more browns, but make sure it’s plain cardboard – none of that glossy-coated stuff – and take the time to shred or rip it up into smaller pieces before adding.
Soggy heaps are a common complaint, and the best way to avoid this is to alternate wetter ingredients like fresh grass clippings with drier materials like cardboard, windblown leaves or woodier crop residues. The resulting mix should be damp but not sodden. You can sprinkle small amounts wood ash onto the heap too, but it must be wood ash – no coal ash.
Something else to avoid is dumping lots of leaves onto the compost heap all at once, which can really slow things down. So add them in modest quantities, along with plenty of fresh green ingredients, or compost them separately over one or two years to make leaf mould.
One way to really supercharge your composting is to include ingredients with a very high nitrogen content. Animal manure or bedding from chickens or herbivorous pets like rabbits or guinea pigs is especially powerful at really firing up decomposition. Nettles are another great booster, while urine is a famously good compost activator – add it direct or as broken up, pee-soaked straw bales.
What Not to Compost
Avoid cooked food waste and animal products like meat and dairy, which can attract rats. If rats do happen to be a problem in your area, it’s also worth avoiding adding potato peelings which are a favourite snack. Weeds are good to go onto the heap, so long as they haven’t set seed, but avoid the roots of pernicious perennial weeds like bindweed. Compost these separately, excluding all light, or drown them in a bucket of water for a few weeks until they’re definitely dead then pour the resulting slop onto your heap.
The composting process needs plenty of air so all the microbes responsible can breathe. One of the best ways to do this is to mix up or turn all of your ingredients once the heap has been filled. This introduces more air and mixes up all those browns and greens. The result is a new lease of life as the compost heap heats up once more to finish rotting everything down in double-quick time. This is where having more than one heap makes things easier, because you can simply dig out the ingredients into a waiting bin, leaving the newly emptied bin ready to fill once again.
Compost heaps that have been mixed also give a finer end product, making the compost a lot easier to spread, which makes all the effort well worthwhile.