Tips on how to calculate how much mulch or compost for your area.

Work out the size of the garden bed you want to cover and multiply this by the depth you need.

Say your garden bed is about 3metres wide by 3metres long, then you multiply 3x3 and know you have 9 square metres to cover.

Next comes the depth. If you want mulch that is, say, 10cm (or 0.1metres) deep then you multiply the size of the garden bed by 0.1m. For your 3x3 bed, that means 3x3x0.1 = 0.9metres, which is just under a cubic metre.

Another way to picture a square metre is to remember it is about 10 good-sized wheelbarrows full.