How to grow potatoes

Video by GrowVeg. This guide is inspired by the popular “Grow Perfect Potatoes Every Time” from the GrowVeg YouTube channel, one of the UK’s most-watched vegetable gardening resources. Benedict Vanheems and the GrowVeg team cover everything from variety selection to earthing up in a way that makes sense whether this is your first year or your fifth.

1. Pick the right variety for the season

Potatoes are grouped by when they are ready: first earlies (ready around 10 weeks from planting), second earlies (13 weeks), and maincrops (15–20 weeks). In a typical UK kitchen garden, first earlies like ‘Rocket’ or ‘Swift’ give you new potatoes by early summer. Maincrops like ‘King Edward’ or ‘Maris Piper’ give you the bigger, better-storing spuds you roast in winter.

Buy certified seed potatoes rather than chitting your leftovers from the supermarket. Certified stock is disease-free and will perform reliably. Most garden centres stock a good range from January onwards.

2. Chit your seed potatoes before planting

Chitting just means encouraging the seed potatoes to sprout before you plant them. Stand them rose end up (the end with the most eyes) in egg boxes or trays in a cool, light, frost-free place — a spare bedroom windowsill is perfect.

Start chitting around February or early March. By the time you are ready to plant in late March or April, each potato should have short, stubby green sprouts about 1–2 cm long. Avoid long, white, straggly sprouts caused by too much warmth and too little light — rub those off and start again in a cooler spot.

3. Prepare the bed and plant at the right time

Potatoes like a reasonably fertile, well-drained soil. Dig in plenty of well-rotted compost or manure the autumn before, or work it into the rows when you plant. They are not fussy about pH, but they do hate sitting in waterlogged ground over winter, so avoid low-lying spots that flood.

Plant first earlies from mid-March in the south, April in the north — soil temperature needs to be at least 6°C. Plant in trenches about 12 cm deep. Space first and second earlies 30 cm apart with 60 cm between rows; maincrops need 40 cm between plants and 75 cm between rows. More room means bigger potatoes.

4. Earth up regularly as the shoots grow

Earthing up is the most important task when growing potatoes and it is dead easy. As the shoots emerge and grow, drag soil up around them to cover all but the top few leaves. Do this every time the shoots grow 10–15 cm. You end up with a neat ridge of soil along each row.

This does two things. It protects the young shoots from late frosts, which can black them off overnight. And it prevents the developing tubers near the surface from turning green — green potatoes contain solanine, which is toxic if eaten in any quantity. Worth taking seriously.

5. Water during dry spells, especially when flowering

Potatoes need consistent moisture, but they do not want to be waterlogged. In dry summers — and Kent can get them — water deeply once or twice a week rather than little and often. A good soak every few days encourages roots to go deeper rather than staying near the surface.

The most critical time for watering is when the plants are flowering, because that is when the tubers are bulking up. A dry patch at this stage can result in small, hollow, or hollow-hearted potatoes. That said, do not panic if you miss a day or two — they are more resilient than they look.

6. Watch for blight and act fast if you see it

Potato blight is a fungal disease that spreads quickly in warm, wet summers — the classic British summer, in other words. The first sign is brown patches on the leaves, often with a white mould on the underside. The foliage can collapse within days.

If you spot blight, cut the haulms (stems and leaves) down to soil level immediately and remove them from the garden. Do not compost them. The tubers will still be fine to eat if you leave them in the ground for two weeks — the skin hardens and the spores cannot penetrate. First earlies are usually out of the ground before blight season, which is one good reason to grow them.

7. Harvest at the right time for the best flavour

First and second earlies are ready when the plants begin to flower. Carefully dig one plant and see what is there — if the tubers are the size you want, harvest them. New potatoes taste best eaten the same day. There is genuinely no comparison.

Maincrops are ready when the foliage has died back completely, typically August to September. Wait for a dry spell, then fork the whole row up carefully. Leave the potatoes on the surface for a couple of hours to let the skins dry and harden, then store in paper sacks or hessian bags in a dark, cool, frost-free place. They should keep well into the new year.

When to call a handyman

Potatoes grow themselves once they are in the ground. The jobs that sometimes benefit from a pair of hands are preparing new growing areas, building raised beds if your soil is poor or waterlogged, or clearing and digging over an overgrown plot before the season starts. Richard can help with all of that.