We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies. You can understand more and change your cookies preferences here.

Home & garden.

11 June 2021

How to grow potatoes

You don't even need a garden to grow potatoes as they can grow in a large pot on a patio or balcony. Discover our best potato varieties and tips for how to grow them.
CT
Ceri Thomas
Muddy potatoes

Potatoes are such a versatile vegetable, from new potatoes with their unique flavour to maincrops that can store all winter and be used for all sorts of dishes, from mash to chips.

How to grow potatoes: month by month

JanuaryFebruaryMarchAprilMayJune

CHITPLANTPLANT
HARVEST
JulyAugustSeptemberOctoberNovemberDecember
HARVESTHARVESTHARVEST


Best potato varieties

Which? members can log in now to see the full results and which are our Best Buy varieties. If you’re not a member, join Which? to get instant access.

Best Buy new potatoes (first earlies)
What it looks likeVariety nameYield from 14 tubers
10kg
Producing some spuds that were large enough to be bakers, this extra-early variety gave us one of the biggest yields in our trial. There was some variability in the size of our harvested tubers, but their excellent flavour and texture means they still came out on top. Last time we tested new potatoes, back in 2013, it didn’t impress our tasters. But in this trial, the thin-skinned, white-fleshed tubers scored well for their texture – smooth and midway between fluffy and waxy – and for their appealing flavour.
What it looks likeVariety nameYield from 14 tubers
8kg
Described by some suppliers as a second-early or even a maincrop, this old French variety from the 1800s is also sold as a first-early and certainly lived up to that billing in our trial. Its smooth, kidney-bean-shaped, elongated tubers were largely untroubled by any pests or diseases and gave us a good yield of even-sized spuds. The yellow flesh had a pleasing waxy texture that would be ideal for a salad potato, with a wonderful flavour that got top marks from our tasters. One described it as ‘delicious with that proper new-potato taste and texture’ – and you can’t say fairer than that.
best Buy salad potatoes (second earlies)
What it looks likeVariety nameYield from 20 tubers
14kg
The highest yielding variety in the trial, it gave a large harvest of uniform, undamaged tubers. It was the only potato that didn’t succumb to blight, although it had started to naturally die back by the end of the trial. The spuds had loose skins that were easy to peel, but tasted fine to eat if left on. Our tasters found the creamy, yellow flesh pleasantly waxy and sweet when served either hot or cold.
What it looks likeVariety nameYield from 20 tubers
12kg
This variety gave a good yield of attractive, purple-tinged tubers that were very regular in size and shape, making them easy to peel and cook. They were good quality, with very few damaged potatoes, and they were also slower to succumb to blight than some varieties. Our tasters really liked the sweet, nutty flavour of the white flesh and commented on the pleasant, waxy and firm texture.
Best Buy potatoes for roasting
What it looks likeVariety nameYield from 20 tubers
30kg
Nicely shaped tubers with distinctive red and white skin gave this variety an interesting appearance, and we got a very good crop of healthy spuds. Our tasters found them excellent for roasting, with a deliciously crisp outside and a light, fluffy middle. The flavour wasn’t quite as popular as the texture. It was described as nutty and buttery, but not particularly distinctive. Be careful not to parboil them too long or they can go mushy due to their Peruvian heritage.
What it looks likeVariety nameYield from 20 tubers
29kg
There were signs of blight in the leaves  by August, but the potatoes had already reached full size by then so they weren’t affected. All the spuds dug up were healthy and usable, and we got a good crop. They held their shape well when parboiled and had a good ratio of outside crispness to inside softness. But where they really excelled was in their taste, which was described as sweet, nutty and flavoursome.
What it looks likeVariety nameYield from 20 tubers
Best Buy potatoes for baking
What it looks likeVariety nameYield from 10 tubers
19kg
This gave a bumper yield of uniform, oval-shaped baking potatoes with smooth, white skins and red eyes. The variety also gave us the most useable potatoes overall, with few showing signs of scab. It was a hit with our tasters, too. They found that the creamy yellow flesh was moist with a sweet, buttery taste. The skin baked to an attractive golden-brown and was packed with flavour.
What it looks likeVariety nameYield from 10 tubers
13kg
If you’re a fan of the skin on baked potatoes then this is a good variety to choose. Though starting off an attractive pale red with golden tints, the skins cooked to a lovely golden-brown colour. Our taste testers told us the skin had a delicious earthy flavour, which was paired with the mild, fresh taste of the flesh. As well as a large crop of red-skinned baking-sized potatoes, it gave us a good yield overall.
Best Buy blight-resistant potatoes
What it looks likeVariety nameYield from 10 tubers
9.2kg
This was a Best Buy when we first looked for blight-resistant varieties in 2009 and is still the best on test. In our trial, the leaves were completely resistant to blight, remaining green and healthy until the trial was over, and only one or two tubers were infected. We got a large crop of big potatoes, which were very floury in texture, so weren’t particularly tasty when boiled, but made good mash.
What it looks likeVariety nameYield from 10 tubers
9.8kg
This comes from the same breeding programme as ‘Sarpo Axona’. The foliage resisted blight almost as well as ‘Axona’, although a few more tubers were blighted. However, this didn’t stop this variety producing a large crop of big, red-skinned potatoes. Our tasters found them a bit more flavoursome than ‘Sarpo Axona’, although not everyone liked the skins.

How we test potatoes

We grow lots of varieties alongside each other and a sample of each variety grown is cooked and assessed for taste. They are then individually tasted by a group of trained assessors, who describe the appearance, smell, flavour and texture of each variety of potato and give them an overall score.

Types of potatoes 

Although any potato will grow and produce a crop, even sprouting ones from the back of the larder, it's best to buy 'seed potatoes' from a garden centre or by mail order. When Which? Gardening magazine compared growing seed potatoes with ones from the supermarket, we found that supermarket potatoes aren't worth growing. They sprout poorly, there's less choice of variety, the variety you want won't necessarily be available at the right time, you'll get a lower yield and poorer quality, there may be disease problems and it's not necessarily cheaper.

Seed potatoes are traditionally sold by weight. A 1kg bag will provide at least 10 tubers - fine for an allotment but too many for a small garden. Look for garden centres that sell small quantities or individual tubers.

Varieties are usually divided into categories according to the speed they produce edible potatoes:

First early potatoes are the quickest to crop and are usually dug fresh and eaten before the skins harden. These are referred to as 'new potatoes' in late June and July.

Second early potatoes are next, from July into August, and include the waxy 'salad potatoes'. Dig these up as required through the summer.

Maincrop potatoes are usually left in the ground until the tops die off and the tubers' skins have set in late summer/early autumn. Dig them up in one go and store them for winter use. Early maincrops will not store much beyond Christmas, so use these first. Late maincrops will take you into spring.

When to plant

Chitting

Unpack seed potatoes as soon as you get them and lay them out on a tray somewhere cool and light. This is known as 'chitting'. Doing it will mean the seed potatoes will grow plump, green sprouts and be ready to grow when you plant them out. Tubers kept in the dark produce long white sprouts that are easily damaged. 

Growing in the ground

Grow potatoes on a different patch of ground each year, over a cycle of three, or preferably four, years. This 'crop rotation' helps to stop any pests or diseases building up. Potatoes are greedy crops (ie they take up lots of nutrients) and growing them involves disturbing the soil - it makes sense to spread this around the veg plot.

Grow early potatoes in rows 40cm apart and maincrops in rows 60-75cm apart. This makes digging the crop easier and means you can earth up the base of the plants in one go.

Plant early varieties in late March in mild areas, or early April in cold areas, followed by second earlies and maincrops during April. Space the tubers 40cm apart.

Potatoes will benefit from a generous amount of well-rotted manure or garden compost. Work this into a trench or spread on the soil surface.

Dig a trench about 25cm deep and 30cm wide. This is especially worthwhile on light soil because you can incorporate some organic matter at the same time.

You don't have to plant potatoes in a trench, but do plant them at least 15cm deep. Remember the new tubers form on the stems above the seed tuber. Use a trowel or an old-fashioned potato planter.

Growing in pots or potato bags

You can grow potatoes in pots, special potato bags or even an old dustbin as long as it has drainage holes. Fill the container with a Best composts for containers with some controlled-release fertiliser until it is about a quarter full. Bury one chitted seed potato near the bottom.

As soon as the potato shoots grow, keep adding more compost until the container is full. Keep the compost moist, but not too wet - if you don't water enough your crop will be small.

To check whether the potatoes are ready to harvest, reach into the compost and feel around. The potatoes are ready when they're the size of an egg.

How to grow big potatoes for baking

Large, evenly sized potatoes are perfect for jacket potatoes. When Which? Gardening magazine looked at the best way to grow this sort of potatoes, we found that the secret is to feed with a general fertiliser, such as Growmore - a 'potato feed' gave poorer results. It's also important to water your plants, especially in dry weather.

Caring for your plants

Protecting from frost

Potato leaves and stems are very sensitive to frost. If a frost is predicted (and a ground frost may occur if the overnight forecast is below 5C), cover the plants with a double layer of horticultural fleece, grass clippings, straw or sacking.

Earthing up

As soon as the shoots emerge, cover them with soil ('earthing up'). This will help increase the number of tubers, stop them turning green, and protect them from frost. Cover them with more earth until there's a ridge around the plants. Alternatively you can use garden compost.

Watering

Watering is needed when you see flowers, but only if conditions are dry. Water about twice a week and give a decent amount. Stop watering when the leaves are showing more than about 10% yellowing, as plants mature.

How and when to harvest

Early varieties will be ready when the foliage just begins to turn yellow. Sometimes, but not always, the tubers will be ready when the plants flower. If in doubt, feel under the plants for egg-sized tubers. 

For maincrop varieties, wait until roughly a third of the leaves are yellow and then lift the crop on a dry day. Work along the row, pushing a fork in from one side and push under the centre of the plants. Take some time to remove all the tubers, not matter how tiny, or they'll grow next year and disrupt that year's crops.

Storing

Early varieties should be eaten straight away but maincrops can be stored for later use. Lay them in a dark place to dry off completely before storing. Remove any that area rotting (especially if blight affected the foliage), damaged or have slug or wireworm holes. These won't keep, so eat them first, once you have cut out the damaged areas. Store the good tubers in hessian or paper bags (sometimes fish and chip shops will give these away). Tip them out every couple of weeks to check over the tubers and remove any that are starting to rot.  

Common growing problems

Blight

Check regularly for black patches on leaves and stems, especially after damp weather. This is most likely to be blight. Cut off all the foliage to stop the fungal spores reaching the tubers. Then leave the tubers in the ground for at least two weeks before harvesting. It's most commonly a problem on maincrop potatoes but can infect earlier potatoes as well.

Read more about blight.

Frost damage

Leaves that have been frosted will suddenly develop brown, dead patches. This is most common earlier in the year when frost is more likely. Your plants should recover. To help prevent it happening, cover the leaves with earth or compost (earthing up) or put on horticultural fleece on cold nights.

Slugs

Slugs can damage the tubers underground, especially on maincrop potatoes in late summer/early autumn. If you suspect this might be a problem, don't wait until you dig up the tubers. The best solution is to treat the area with a biological control such as Nemaslug as this will reach slugs underground.

Read more about slugs.

Wireworm

Wireworm can also burrow into the tubers and cause similar damage to that caused by slugs. Look for shiny brown grubs. These are common on a new veg plot that was previously under grass. The problem should disappear after a couple of years. 

Read more about wireworm.

Blackleg

Blackleg symptoms include leaves that are small and yellowed, and may be distorted. The stem base shows distinct blackening and then dies back. The vascular stands are blackened so cutting the stem across reveals black 'dots'. The 'mother tuber' rots completely and if it strikes early, the plant may be killed and will not crop. Wet soils tend to exacerbate the problem.

Read more about blackleg.

Common scab

Dry soils and dry summers are a favourite of scab.  It produces corky irregular wide and flat bumps, often in groups. These are frequently pitted and covered in scabs. Stems are also attacked, but not noticeably. 

Read more about scab.

Powdery scab

Common in wet weather and on heavy soils, powdery scab is less common than common scab.  It causes raised irregular scabs which release a powder of spores. This powder is brown and the spores can survive for as long as 10 years in the soil. Before the scabs burst, there may be surrounding areas of discoloured skin. In extreme cases cankers form, disfiguring the tubers with large outgrowths. 

Read more about powdery scab.

Black scurf

Black scurf is a fungal disease which damages early potato shoots in cold, wet soils. Look out for black speckles, which can be scraped off the tubers. Earlier in the season, watch out for brown stem bases; these infected areas may go right around the stem. The leaves become rolled and wilted. A white powdery collar can sometimes be seen around the stem at ground level, too. In severe cases, where they are planted in cold soils, the young sprouts are killed and the crop does not survive.

Read more about black scurf.

Jobs to grow potatoes for January and February

Jobs to grow potatoes throughout the year