Earthing Up Potatoes and Mulching Methods

In May, many of us will be turning our attention to our emerging potato plants and earthing up around the plants to increase the number and quality of the tubers. With our earliest potatoes, we may be earthing up for the second time. Whether we are growing potatoes in the ground or in a raised bed, grow bag or other container, the techniques will be more or less the same. The aim is to make sure that light is excluded from growing tubers and to give them room to grow.

Traditionally, potatoes will be earthed up with soil or compost when they emerge and again when they are around 23cm tall. This is a tried and tested method and will work as long as you have a space from which you can take the soil needed to earth up, or a ready supply of compost. Those who are utilising permaculture practices such as companion planting and layering through time may find that soil is at a premium. No-dig practices involve disturbing the soil as little as possible. For this reason, many organic gardeners are choosing to use alternative methods with their potatoes.

Rather than piling up earth around the potato plants, some gardeners around the world are choosing instead to bank up a thick mulch around the crops. This mulch serves a number of purposes. It will of course serve the same purpose as the soil in earthing up, providing space for and excluding light from the growing potato tubers. It will also add nutrients to the soil, slowly feeding the plants it surrounds. What is more, a mulch can help to retain moisture in the soil as the weather warms up, and water is crucial for growing spuds.

Straw is one popular choice for mulch, hay can also be used. Basically, potatoes can be mulched with whatever materials you have to hand that are plentiful in your environment. Coastal communities can have great success mulching with seaweed and some areas may have success with bracken if this is more readily available locally than straw. Mulching methods can be many and varied and gardeners have had great success with a wide range of different techniques. By topdressing soil in this way, you can find that potatoes are close to the soil surface and easy to harvest when the time comes. This can also be a good chance to address any insufficiencies in your local soil.

As with any gardening technique, trial and error are essential. A little experimentation can help you to discover the techniques and practices that work best where you live. What works well in the south of England will not necessarily work well in the Scottish Highlands, and vice versa. Potatoes are something that will grow well in a range of conditions and so are the perfect crop to use for some simple garden experiments. Why not trial some different mulches this year and see what works well for you.