Interactive lesson

Potatoes and roots, step by step

Interactive lesson: potatoes from field to cellar, curing, sweetened and sprouted potatoes, carrots and beetroot in sand, checks and the order of use.

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The whole lesson as text

1. From field to cellar

Winter potatoes need a set skin, and winter is decided back in September.

Lift in dry weather — Lift when the haulm has died right back, or 2–3 weeks after cutting the haulm, once the skin no longer rubs off under your thumb. Dry off 1–2 hours, no longer.
Three heaps at once — Sound, firm, medium-sized tubers go for winter. Cut and scuffed ones go to the kitchen within 2–4 weeks. Small and green ones are cooked for the animals or go on the compost.
Curing 10–14 days — Keep the potatoes in shade, with air moving, at 12–18 °C and high humidity, covered with hessian sacks or cardboard.
Cool down day by day — If the cellar is still warm, keep the potatoes in a shed aired at night, covered from light and frost. They go into the cellar once it drops below 6–8 °C.

Why: Uncured potatoes lose water through their wounds in the cellar and rot. Curing heals the scuffs, hardens the skin, and diseased tubers show up before they infect the rest.

Put tubers with spots and rot into a separate, closed bag and look at them closely.
Suspected brown rot or ring rot must be reported to the plant health authority (H14-05, chapter “Notifiable diseases and pests”).

2. Potatoes in the cellar

Potatoes want a cold, damp and completely dark place.

At 4–6 °C — At this temperature the tubers stay dormant longest. Humidity 90–95 %.
In complete darkness — Cover the crates with hessian or cardboard so no light reaches them when you switch on the lamp.
Crates and a bin — Wooden crates of 25 kg or a slatted bin with a floor 10 cm off the ground. Moisture and heat escape through the slats. A layer of 40–50 cm at most.
No apples or pears — Fruit gives off ethylene, so potatoes sprout sooner and carrots turn bitter. Keep fruit separate.

Why: Below 3 °C potatoes turn sweet, above 8 °C they sprout. In light they go green and form solanine, and in dry air they shrivel.

Use hessian sacks only for a short time and do not stack them.
A layer deeper than 50 cm heats up and sweats, and too little air gives the tubers a dark centre.