Last Autumn, Tracey planted some seed potatoes in the polytunnel to see if they'd be happy through the Winter and find out if they'd emerge in the Spring. Well, they certainly look well enough. We gave them a good watering today, just to help the underground tubers to swell into something big and delicious. We also earthed them up: that is, we piled more soil over the greenery. This encouraged the plant to produce more potatoes and keeps the sun from getting through to the tubers which would turn them green and unuasable.
Actually, I could have told Tracey they'd grow. Every year, when I dig up my potato crop, I somehow always manage to miss a few. The following year, the forgotten tubers grow and emerge into the sunlight, usually in the most inconvenient place such as a recently-sown seedbed of the following crop.
Unlike me, Tracey had the good sense to put her potatoes exactly where she wanted them to grow.