The first job is to chit your potatoes, any time from Feb to May. Ideally use seed potatoes which are guaranteed to be disease-free, but you can try with spuds from your greengrocer. Egg boxes are ideal for chitting. Leave them in a cool dry spot and when they start to shoot you're good to go.

Add a layer of broken bricks or gravel to the bottom of the planter then half fill with compost. Evenly space four potatoes, eyes up, and then fill almost to the top with compost. When leaves appear, fill any remaining space in the planter with compost and water occasionally. A weekly soak is better than a daily shower.

The shoots will die back if they get too cold, so if there is a frost forecast cover for the night with a fleece or sack.

If you like small potatoes, harvest as soon as they flower. If you prefer them larger, wait a week or two after flowering.