Using biodegradable mulch sheet

Although this photo is from a garden in summer, using a biodegradable sheet mulch like this can work really well in autumn and winter too, by keeping the soil a little warmer. Many gardeners will use this method using black polythene sheets, but these biodegradable sheets provide a slightly more environmentally-friendly solution. Most are made using corn starch, and will start to break down approximately 6 months after being laid down.

Why use mulch sheet?

It can be a very helpful way to grow if you either struggle with keeping weeds down, or, if you’re growing in colder parts of the country. It works by blocking light, and because it is black, it also helps to warm the soil. This is great for autumn and winter growing if your plot tends to be very exposed to frost, and if you’re in an area that is more prone to snow. Here in Cornwall, that’s not such an issue, but for those of you growing vegetables further north, you might find the use of mulch sheet is invaluable over autumn and winter. Warmer soil is much kinder on plants, and you’ll find the growth much accelerated as a result.

How to use it

Pull up the worst of the weeds before laying the sheet down on top of a raised bed. The best way to secure it down is to bury the edges under the soil, or use heavy stones. Once it is in place, cut a small hole where you want to plug a plant in place, and plant through the sheeting this way (it’s easily done by cutting a cross using a pair of scissors.) Be sure that the hole is not much bigger than the root ball, as you want to keep as much of the soil covered as possible.

What plants is it suitable for?

Any. Whether you’re planting a whole load of winter brassicas, or salad leaves, you can use this quite happily.

What about watering?

At this time of year, with frequent rainfall you won’t need to worry much – the rain will reach the plants through the holes that you have cut, and the mulch sheet will hold most of the water in the soil, as it won’t have a chance to evaporate.

Where to find it

You’ll be able to find rolls of biodegradable mulch sheet easily online – just do a quick search and you’ll find plenty of suppliers. Some garden centres now sell it by the metre as well.