Allottolearn: Earthing Up

With a new year comes a new series. This is going to be a series of 10 posts supplied to you over the next 10 weeks on specific things of interest, ranging from techniques you may have heard of, or interesting locations to travel to. So let’s begin the new year with an interesting technique: Earthing Up.

There are many fantastic vegetables that can be grown in your garden, but for the best results, it is important that you know how to best care for the vegetables you are growing. If you are thinking of growing potatoes at home during the next growing season, earthing up potatoes is an essential component of the potato growing process, even when container growing.

What is earthing up?

The earthing up process is, in essence, drawing mounds of soil up and around the plant. You need to do this to maximise the likelihood of new tubers growing under the soil. This task ensures that your potatoes don’t turn green and poisonous (which happens if the potato tubers grow in the sunlight): an outcome that all gardeners should look to achieve!

Earthing up potatoes will help to increase the yield of potatoes, which grow from the stems that have been buried. Another benefit of earthing up potatoes is that it will help to minimise the likelihood of infection to the tuber. Therefore, gardeners should consider earthing up potatoes to be a crucial step to safeguard and improve the health and growth of potatoes in their garden.

The best time to earth up potatoes is before the tubers start to turn green. If tubers have started to turn green, they are inedible, and they could be poisonous. A good guide for the start of the earthing process is to start when the shoots of your plant are around 8 inches or 20 cm long. You may want to earth up multiple times within the season however, I would recommend keeping earthing up whenever you can see bare stem over 2 inches at the base of the plants.

Use the right equipment when earthing up

You will find earthing much easier if you use a hoe. This should be used to draw the soil into mounds around the potato plant stems. You should look to use a sufficient amount of soil that leaves around 2 inches or 5cm of stem visible above the ground.

This is a suitable length because it ensures the tubers are deprived of light, which will prevent them from turning green, but it also provides enough foliage to enable the plant to grow at a reasonable rate. At this stage, you should also look to remove any weeds that have appeared since planting, as all these are doing is sapping up the nutrients from the soil.

Watch out for rainfall when earthing up potatoes

It is vital that you maintain your mound and you should keep a close watch on your potatoes. If you experience heavy rainfall in your area, this may wash away your mound. If this happens it will have to be replaced. To minimise the likelihood of this occurring, do not build the mound too tall for its width. A shallow triangle is perfect for stability, a pyramid is somewhat ambitious and will erode in the weather.

You should repeat the earthing up process when there is a growth of around 4 to 6 inches, or 10 to 15 cm, above the ground. Depending on the growth of your plant, you may need to earth up your potatoes three or four times in the same season.

Growing in containers

During the last year I grew my potatoes in bags, which were absolutely perfect. However earthing up is still a necessity. I followed the above concept, topping up the soil in the bag. I stopped when I filed the bag to the brim. This worked! The end result was a much larger crop of potatoes than I expected.

The second great thing about container growing is that you do not need to worry about weather erosion. The soil is all contained!

Potatoes are a highly popular choice and a relatively simple vegetable to grow. As such it is understandable that many gardeners are keen to plant them. To maximise your return when growing potatoes, make sure you are comfortable and confident earthing up your potatoes.

Look forward to enjoying your home grown food.