There’s more to choosing a compost bin than you’d imagine though frankly I suspect certain units have been designed by someone who didn’t know one end of a trowel from the other.

When selecting a new compost bin, bear the following in mind. Can you assemble it without bursting a blood vessel? Will it accommodate your garden waste and fit in the allocated space? Is it easy to get finished compost out of? I’ll only look at affordable bins that’ll give you good results in a reasonable time – within a year or so.

Undoubtedly, the simpler the design, the easier a composter is to assemble. Units such as the Rotol and Blackwall’s come as all-in-one circular bins ready to plonk straight on the soil wherever you like.

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When assembling square or hexagonal composters, the sides should click together fairly easily, provided the ground is level. It’s a bit harder when the sides are joined together by long black pins, running from the top of the bin to ground level. And, frustratingly, bins do seem to change shape over time so you may struggle in future to replace pins or clips.

Compost bins come in many sizes, so tailor the unit to what you need for your garden. They range from 200 litres to 1500, with larger ones working faster and at a higher temperature.

Shape also matters. For best effect, composters need as much sun as possible, and most of a round bin gets heated up as the sun crosses the heavens, but regardless of where you site a square bin only three sides are exposed to sunlight. I’ve found round units work at significantly higher temperatures than their square equivalents.

When it comes to overall design, I’m convinced manufacturers vie with each other to produce the most elaborately-shaped slats possible. No effort is spared over twists and twiddles, all in the name of good air circulation. And an array of holes is added to the mix.

The manufacturers are right to emphasise the importance of air circulation, as the vital aerobic bacteria need fresh oxygen to function. But it’s worth remembering that, for a bacterium, an air space measuring 0.05mm is vast.

All the bacteria need is a loosely packed pile of material. You introduce enough air when emptying a compost bin and, as a special treat, you could stick a garden fork into the heap and shuggle the top foot or so.

Fancy air holes and designs are not only completely unnecessary, but they also dry out the compostables next to the hole. Check out the corners of a square bin or holes at the side of a slatted wooden composter. You might even find weeds growing out of them.

Most compost bins have hatches for extracting the compost that’s ready. They’re usually so flimsy, they’ll readily fall off. I’ve yet to meet someone who succeeds with these hatches. After digging out the first two or three spadefuls of fine, crumbly compost, the partly composted material above falls into the hole you’ve just made. And, it’s nigh impossible to get at the compost at the back or sides of the bin. I may be inept, but I’m not the only one.

If you have a rounded 200l or 300l composter ready to empty, start by sealing up the hatch and then lift the bin off the heap. Fork the material that isn’t ready yet to one side and then shovel away all the good stuff at the bottom – easy. Then refill the bin with the partly composted ingredients.

For square or hexagonal units, swing one side like a door by removing the retaining clips or pegs then empty them as you would with the circular types.