Top job for June: Earthing up potatoes

The leaves and stems will also be growing rapidly. Although they no longer need protecting from being ‘knocked back’ by frost, they can be encouraged to produce even more potatoes by a very simple method called ‘earthing up.’

Earthing up potatoes is exactly what it sounds like. It involves piling up soil over the growing leaves and stems but leaving approximately 10cm of the growing plant exposed to sunlight. Depriving the plant of light encourages it to increase the length of its stems growing underground. It’s these stems on which potatoes grow, so the longer the underground stem the greater the chance of it producing more potatoes.

The method of earthing up potatoes can be done when they are planted and then repeat the process when the first signs of foliage appear.

Then, you should be able to do this twice more during the growing season at two-week intervals. You can use garden soil or compost to cover the leaves and stems by piling up in a mound formation over them.

When doing this process, ensure the crops are kept well-watered, especially if we’re experiencing long, dry periods. It’s also ideal to add a fertiliser that’s rich in nitrogen at the point of the second earthing up.

Another bonus of doing this is that it helps keep weeds at bay. By keeping the plants covered, it stops potatoes turning green which happens when they’re exposed to the light. If potatoes turn green, they can be poisonous and inedible.