Grow potatoes in an open, sunny site in well-drained soil. Plant early varieties one month before the last frosts are predicted, and main-crop types in late spring.
When to Start: Late winter to spring, depending on variety
At Their Best: Summer
Time to Complete: 3 hours over a few months
In late winter, buy your seed potatoes and place them in egg crates in a cool, light, frost-free place to "chit" or sprout. They'll start growing while it's still too cold to plant them out.
Dig a trench to a shovel's depth, and fill the bottom with loose soil or compost. Plant early varieties 12 inches apart, in rows 20 inches apart, and main-crop varieties 16 inches apart, in rows 30 inches apart. Cover them with soil.
As potato plants grow, their stems should be regularly covered with soil or "hilled up." In the early days, this protects the tubers from frost. Later on, it encourages the growth of extra tubers, leading to a larger crop. Hilling up also prevents the tubers from being exposed to light, which makes them turn green and inedible.
When seed potatoes are first planted out, hilling up may not provide enough protection from frost. In colder regions, add a layer of straw to prevent tubers from freezing.
When the flowers begin to open, your potatoes are ready to harvest. Use a garden fork to dig them up from below, accessing them from the side of the mound, to avoid damaging them.
Main-crop potatoes can be stored in paper sacks. After harvesting, brush off the soil and dry in the sun for a few hours. Pack away only the perfect tubers in a cool, dry area and check them regularly.
Excerpted from How to Grow Practically Everything
© 2010 Dorling Kindersley Limited