Composting Masterclass with Monty Don

The real secret of compost is that it gives life to soil. Because compost is made by material being digested by bacteria and fungi and nematodes and the brambling worms and beetles and slugs. And you can make it work like a recipe that you know just works and works every time. First thing, your ingredients. You can add almost anything that's lived to a compost heap, but don't add meat, fats or cooked material, particularly cooked starches like potato or rice or pasta. But almost everything else from the garden and the house can go on. So for example, kitchen waste, eggshells, banana skin, vegetable pairings, all can definitely go on. Typically, the most common compostable material that people have are grass clippings. And that certainly is really important. But that is all green material, very high in nitrogen. And if you just have this sort of waste, what you'll end up with is a sort of green sludgy slurry. And that's because it's short of oxygen and carbon. Now, carbon comes from brown material. And at this time of year, there's a lot of it. You've got all the dried stems of plants. You can use brown paper. You can use egg boxes. And if you've got cardboard, don't just put it in flat, but rip it up. And you need to mix the green material and the brown material on at least a 50-50 basis. Now, you can just mix them up and it'll work fine. But if you can chop them up or shred them, it'll work much better. And then you end up with this. And you saw in the bins how that when I disturbed it, there was steam rising up. Now, that steam is heat generated by the trillions of creatures digesting it. But to work successfully, they need water. So don't let it get too dry. And they need oxygen. So leave it for about three or four weeks and then turn it so lots of air can get in there. And if you turn it a couple of times, you get to this point. It's not perfect. There are bits and pieces there that hadn't composted at all. It's a bit stuck together. This is fine to use around hedges or shrubs or to spread on the border in autumn as a mulch because over winter, that will break down and be incorporated into the soil. But if you want to put it onto a vegetable garden in spring or summer, or use it as part of your potting compost, you need to turn it again. And this is how it can become. And what this is doing is adding life to the soil. And when you put an inch layer over the soil, it's like a starter dough. It recharges the soil. And that extraordinary complex relationship, which I don't begin to understand, between life in the soil and the roots of plants is what makes your garden grow.