Our compost bins work faster when we keep them hot. This partly depends on air temperature. So whatever we do in Shetland, composting is slower than in Eastbourne and that’s a snail’s pace compared with Malaga.

And the time of year is also critical. As I write, my New Zealand box registers 15C, twice today’s air temperature, but only a third of what I’d expect in the summer.

The sun is pivotal. With our weaker sun in Scotland, we need as sunny a spot as possible for our composters; partial shade is not ideal. You can, of course, make compost behind a shed, but don’t expect a result any time soon.

A bin’s shape also matters. The rounder the better, as the sun shines on most of it during the course of the day. It can never reach one side of a square one.

When filling the composter, try to ensure there’s a good mix of green sappy material, such as weeds and kitchen scraps, with brown, woodier material, such as paper and plant stalks.

Too much green gives you a soggy, smelly mess and virtually no composting occurs with only dry browns. A green-brown balance gives you a damp, healthy brew.

Also, compost activator won’t wave a magic wand and transform large lumpy bits of sprout stalk into mouth-watering compost. It gradually speeds up a reasonably working pile, but there are plenty of free methods to use.

The smaller the individual pieces you add, the better. This is because there are many

more exposed edges for

micro-organisms, such as bacteria, to work on. They then reproduce rapidly, leading to a larger workforce. At a later, cooler composting stage, creatures, like worms, also graze round the edges of materials and this extra food leads to an increase in their numbers.

So these larger populations produce quicker results.

Everyone knows that you get faster composting by turning the heap to inject fresh oxygen. This works with New Zealand boxes and can be done as often as your back can stand it. But small plastic units should not be treated this way.

Here there is fresh material at the top and finished compost at the bottom: the last thing you want to do is mix it all together.

To turn this compost, simply thrust a garden fork into the bin to the depth of the tines and shoogle around a few times. Do this as often as you like.

When emptying the bin, fork out the unrotted material and remove compost from the bottom and refill.

Grass is an excellent activator. Fresh clippings are roasting hot, registering a full 60C, so every time you cut the lawn, stick a couple of grass boxes in the composter and use a fork to mix in with the rest of the pile.

Don’t let all this heat escape. Ideally, you’d cover a New Zealand box to keep the top moist and prevent heat loss. But whether you can face the hassle of taking a cover on and off every time you empty a bucket of weeds is up to you.

But do have solid sides to your bin. Pallets are fine, but you lose a lot of heat through the gaps, the compost dries out and weeds germinate. Cover the gaps with strips of wood or line the inside with cardboard.

Also line the sides of plastic composters with cardboard if there are holes in the sides or gaps for fastenings.

This dries out the material and slows composting; it doesn’t and couldn’t inject air into and through the material, as is often said.