When to start: Late winter.
At their best: Summer.
Time to complete: 3 hours over a few months.
You will need: Seed potatoes, egg crates, well-rotted organic matter – such as compost or manure, string, spade, straw or other dry mulch.
Chit seed potatoes
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 will start growing while it is still too cold to plant them out.
Planting depth and distance
Dig a trench to a spade’s depth, and fill the bottom with loose soil or compost. Plant “first earlies” and “second earlies” 12 in (30 cm) apart, in rows 20 in (50 cm) apart, and “maincrops” 16 in (40 cm) apart, in rows 30 in (75 cm) apart. Cover them with soil.
Add more soil
As potato plants grow, their stems should be regularly covered with soil or “earthed 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. Earthing up also prevents the tubers from being exposed to light, which makes them turn green and inedible.
When seed potatoes are first planted out, earthing 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 fork to dig them up from below, accessing them from the side of the mound, to avoid damaging them.
Tips: Storing potatoes
Maincrop potatoes can be stored in paper or hessian sacks. After harvesting, brush off the soil and dry in the sun for a few hours. Pack away only the perfect tubers and check them regularly.