Potatoes, step by step

1. How many potatoes, and what kind

First work out how many potatoes you need, then get only healthy seed potatoes.

1. How many potatoes — An adult eats roughly 80 kg of potatoes a year. That's about 32 m² of field per person.
2. The winter store — Of that, 50–60 kg goes into the winter store. For the cellar, choose varieties with long dormancy, which sprout less before spring.
3. Certified only — Certified seed potatoes carry an official label with the variety, class, lot number and grower (in the UK under the Seed Potato Classification Scheme, in Ireland DAFM, in the US state certification, in Canada CFIA). Keep the label.
4. Not from the supermarket — Potatoes from the supermarket or market are ware potatoes: often treated with sprout suppressants, of unknown health. Don't plant them.

Why: Potatoes give more food per m² than anything else planted in a field and feed a family from September to May. But almost everything travels with the tuber: viruses, bacteria, fungi and nematodes. So the seed potatoes are the most important decision of the whole year.

• Grow at least two varieties: a first early on 10–20 % of the area and a maincrop for winter. Blight-resistant varieties such as Sarpo Mira or Carolus (Defender or Elba in North America) are worth the extra cost.
• Renew your own tubers every 2–4 years and don't sell or give them away: marketing seed potatoes is regulated by law in the UK, Ireland, the US and Canada.

2. Seed tubers and chitting

Chitting shortens the time to lifting by 2–3 weeks.

1. A tuber like an egg — A seed tuber is 35–55 mm and 40–70 g, like a hen's egg. For 100 m² you need about 25–30 kg (55–65 lb).
2. Trays, eyes up — 3–6 weeks before planting, set the tubers in shallow trays or egg boxes, eyes up.
3. Light and 10–15 °C — Keep the trays in the light, but not in direct sun, at 10–15 °C.
4. Short, sturdy sprouts — Good sprouts are short and sturdy, dark green or purple, 1–2 cm. When planting, carry the trays to the field and take care not to break them.

Why: Chitted potatoes give the plant a head start on blight and beetles. Long, white, thin sprouts from a dark cellar break off and are no good.

• If you cut tubers, each piece must have 2–3 eyes and weigh 40–50 g, and after each tuber disinfect or boil the knife.
• Throw tubers without a single healthy sprout or with rotten patches in the bin, not in the compost.

3. Soil and planting · Locked

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4. Earthing up and water · Locked

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5. Blight and Colorado beetle · Locked

Buy the Potatoes from planting to clamp module and you get the PDF to download and print, plus lifetime access to this interactive lesson: all 6 chapters, 24 steps.

6. Lifting and winter · Locked

Buy the Potatoes from planting to clamp module and you get the PDF to download and print, plus lifetime access to this interactive lesson: all 6 chapters, 24 steps.