The big facts page

101 potato facts, all checked

Every fact on this site in one place, each linked to its source. Our build checks each one against the source text; see the sources page. Things that can change carry the date we checked them, and where sources disagree you’ll find both.

Growing

1 Potatoes are a traditional veg plot staple, easy and fun to grow, producing plentiful crops in summer and autumn. RHS: How to grow potatoes
2 Most varieties are classed as either earlies (new potatoes) or maincrops, depending on when they’re ready to harvest. Earlies are split into first and second earlies. RHS: How to grow potatoes
3 Potatoes are grown from specially prepared “seed potatoes” (small tubers) that are certified virus-free. RHS: How to grow potatoes
4 Garden Organic says not to plant sprouted potatoes from the kitchen: they are not certified and may bring potato viruses and diseases into your garden. Garden Organic: Potatoes growing guide
5 Early varieties are faster growing, ready to harvest in as little as 12 weeks, take up less space and can be grown in containers. RHS: How to grow potatoes
6 Maincrop varieties stay in the ground much longer, give a bigger harvest and bigger potatoes, and can be stored for use in winter. RHS: How to grow potatoes
7 Earlies are harvested by midsummer, which frees up space for a later crop such as courgettes or beans. RHS: How to grow potatoes
8 The RHS suggests looking for varieties with an Award of Garden Merit (AGM), which performed well in trials. Its list includes ‘Charlotte’, ‘Maris Piper’, ‘Pink Fir Apple’ and ‘Sarpo Mira’. RHS: How to grow potatoes · checked 29 Oct 2026
9 Potatoes need an open, sunny site that isn’t prone to late frosts, because the young shoots can be damaged by frost in April and May. RHS: How to grow potatoes
10 Potatoes like rich, fertile soil, so dig in plenty of organic matter such as garden compost or well-rotted manure before planting. RHS: How to grow potatoes
11 Garden Organic says soil pH should ideally be around 6.5 or lower. Garden Organic: Potatoes growing guide
12 Chitting means letting seed potatoes sprout before planting. It isn’t essential, but is worthwhile with early varieties for an even earlier crop. RHS: How to grow potatoes
13 For first and second earlies, start chitting in late January in milder areas and up to early March in colder spots. It takes four to six weeks. RHS: How to grow potatoes
14 Stand the tubers in egg boxes or seed trays with the buds (eyes) uppermost, in a bright, frost-free place. RHS: How to grow potatoes
15 Unchitted early potatoes still grow perfectly well, but take a few weeks longer to crop. There’s no real advantage to chitting maincrops. RHS: How to grow potatoes
16 Garden Organic: chits in a dark corner come out as white shoots, and too much light makes them long and easy to break off. Garden Organic: It’s time to chit your potatoes!
17 RHS planting times: first earlies around late March, second earlies early to mid-April, maincrops mid-April to early May. Plant a little later in colder regions. RHS: How to grow potatoes
18 Garden Organic says the soil should be at least 6C (43F) at planting. A good sign is when grass and weeds begin to grow. Garden Organic: Potatoes growing guide
19 Plant in a trench 15cm (6in) deep, sprouts upwards, then cover with soil and water well. RHS: How to grow potatoes
20 RHS spacing: earlies 30cm apart in rows 60cm apart; maincrops 37cm apart in rows 75cm apart. RHS: How to grow potatoes
21 Grow potatoes in a different part of the plot each year. Crop rotation helps avoid a build-up of diseases and other problems in the soil. RHS: How to grow potatoes
22 Garden Organic says not to plant potatoes in the same ground with less than a four-year gap. Garden Organic: Potatoes growing guide
23 No-dig gardeners can shallow-plant seed potatoes under a deep layer of organic matter, then harvest by pulling the potatoes out of the mulch. RHS: How to grow potatoes
24 In containers, early varieties are the most suitable. Use a container at least 30cm (12in) wide and deep, with one seed potato per 30cm of pot width. RHS: How to grow potatoes
25 Garden Organic suggests five tubers in a dustbin-sized container, or one to three in a 30–40cm container or compost bag. Garden Organic: Growing potatoes in containers (A12, PDF)
26 Earthing up means mounding soil around the stems as they grow. It protects shoots from frost and keeps light off the developing potatoes, which would turn them green. RHS: How to grow potatoes
27 RHS: when shoots are about 23cm (9in) tall, draw soil up to form a ridge, leaving the top 10cm showing. Repeat a few weeks apart, to a final ridge of 20–30cm. RHS: How to grow potatoes
28 Garden Organic: earth up first when plants are around 15cm tall, leaving about 5cm showing, and again just before the foliage meets across the rows. Garden Organic: Potatoes growing guide
29 If frost is forecast after shoots appear, cover them overnight with a cloche, hessian or straw, or with soil or compost. RHS: How to grow potatoes
30 Weed for the first month or two. Once potato plants are growing strongly they usually shade out the competition. RHS: How to grow potatoes
31 Water potato plants in dry weather. Containers need regular watering, even in wet weather, because the leaves can act like an umbrella. RHS: How to grow potatoes

Harvesting and storing

32 RHS harvest guide: first earlies June and July, second earlies July and August, maincrops late August to October. RHS: How to grow potatoes
33 Harvest earlies when the flowers are open or the buds drop. The tubers should be the size of hens’ eggs. RHS: How to grow potatoes
34 Before digging, gently scoop away some soil to check the size of the tubers, and cover them again if they aren’t big enough. RHS: How to grow potatoes
35 Insert your fork at least 30cm (1ft) from the base of the plant to avoid spearing the tubers. RHS: How to grow potatoes
36 The RHS says to discard any potatoes that are green. RHS: How to grow potatoes
37 To store maincrops, wait until the leaves turn yellow, cut off the top growth, wait 10 days, then dig up the tubers and dry them in the sun for a few hours. RHS: How to grow potatoes
38 Garden Organic: maincrops store best if left in the ground for two to three weeks after the haulms (stalks) have died back. Garden Organic: Potatoes growing guide
39 Store only undamaged, dry potatoes in a cool, dark, frost-free place, in paper or hessian sacks or on slatted trays. Check every few weeks. RHS: How to grow potatoes
40 Aim to finish stored potatoes before early spring, when they start to sprout and shrivel. RHS: How to grow potatoes
41 Early potatoes are best used as soon as possible after harvesting. RHS: How to grow potatoes
42 For a Christmas crop, plant cold-stored seed potatoes in July or early August, in a large container in a greenhouse or bright frost-free place. RHS: How to grow potatoes
43 For an extra-early crop, plant chitted earlies in large containers in a frost-free greenhouse at the beginning of March, for a crop by about mid-May. RHS: How to grow potatoes

Pests and problems (some dated)

44 Potato blight (late blight) is caused by a fungus-like organism, Phytophthora infestans. It spreads rapidly through leaves and tubers in warm, wet weather. RHS: Potato and tomato blight
45 The RHS calls blight the most serious and damaging disease of potatoes. It can also affect tomatoes. RHS: Potato and tomato blight
46 The first sign of blight is a fast-spreading, watery rot of the leaves, which collapse, shrivel and turn brown. Infected tubers have a reddish-brown decay under the skin. RHS: Potato and tomato blight
47 First earlies are more likely to escape blight, because the disease tends to increase as summer goes on. RHS: Potato and tomato blight
48 When about 25 percent of leaves are affected, or stems show lesions, cut off the foliage (haulm). Dig the tubers about two weeks later, once the skins have hardened. RHS: Potato and tomato blight
49 Blighted plants should be deeply buried, put in council green waste or burned, not composted. RHS: Potato and tomato blight
50 Gardeners can check blight forecasts for their area on the BlightSpy website. RHS: Potato and tomato blight · checked 29 Oct 2026
51 Early blight is a different disease, common in North America but not a common problem in British gardens. RHS: Potato and tomato blight
52 Common scab and powdery scab cause rough, scabby patches on potato skins. Common scab is worse in dry soil when tubers form; powdery scab is worse in wet conditions. RHS: Potato scabs
53 To reduce common scab, the RHS suggests watering from 2–3 weeks after emergence for about four weeks, at 20 litres per sq m. It is worse on alkaline soil. RHS: Potato scabs
54 Blackleg is a bacterial disease that causes black rotting at the stem base. It can show as early as June, especially in wet years, and only infects potatoes. RHS: Potato blackleg
55 The most important blackleg control is to remove and destroy infected plants as soon as symptoms appear. There are no chemical controls for gardeners. RHS: Potato blackleg
56 Slugs particularly like to tunnel into maincrop tubers during damp autumn weather. RHS: How to grow potatoes
57 Slugs and snails also help recycle dead leaves in gardens and are food for birds, beetles and reptiles. The UK has over 44 species of slug and 90 of snail. RHS: Slugs and snails
58 Colorado beetle was declared eradicated from the UK on 11 December 2025, after it was found in Kent in July 2023 and none were found for two years. GOV.UK (Defra/APHA): Major potato pest eradicated from UK (11 December 2025) · checked 29 Oct 2026
59 Colorado beetle is orange-yellow with 10 black stripes. It can strip the leaves from potato plants. Suspected sightings should be reported to the Animal and Plant Health Agency with a photo and location. GOV.UK (Defra/APHA): Major potato pest eradicated from UK (11 December 2025)
60 Colorado potato beetle was first recorded in the USA in 1811 and first became established in Europe at Bordeaux, France, in 1921. GOV.UK (Defra/APHA): Colorado potato beetle confirmed in Hampshire

The plant

61 Potatoes are tubers: storage organs the plant uses to store nutrients and water so it can regrow the next season. Royal Botanic Gardens, Kew: Potato season at Kew
62 Potatoes belong to the nightshade family, the same family as peppers and tomatoes. Royal Botanic Gardens, Kew: Potato season at Kew
63 Underground stems called stolons swell at their ends to form a few to more than 20 tubers. Encyclopaedia Britannica: potato
64 The “eyes” on a potato are buds. They sprout to make new plants that are clones of the parent. Encyclopaedia Britannica: potato
65 Potato flowers are white, lavender or purple, with five joined petals and yellow stamens. The fruit is a small poisonous berry with many seeds. Encyclopaedia Britannica: potato
66 The potato plant grows up to 100cm (40 inches) tall. Its leaves make starch, which is moved to the ends of the underground stems. International Potato Center (CIP): Potato
67 Each tuber has from two to as many as 10 buds (“eyes”), arranged in a spiral. International Potato Center (CIP): Potato
68 There are between 100 and 180 wild potato species. They are too bitter to eat, but carry natural resistance to pests, diseases and climate. International Potato Center (CIP): Potato
69 In the Second World War, Kew’s curator William Campbell found that potatoes could be grown from slices, as long as each slice had an “eye”. Royal Botanic Gardens, Kew: Potato season at Kew
70 The National Allotment Society calls potatoes an excellent crop for beginners: easy to grow, they help break up the soil and need little maintenance. National Allotment Society: Best crops for first-time allotmenteers
71 The National Allotment Society lists potatoes as a great beginner crop, good for breaking up compacted soil. National Allotment Society: Start your allotment with confidence
72 Kew says potatoes enjoy a cool climate, which reduces fungal diseases such as blight, and that this is why a lot of seed potato is grown in Scotland. Royal Botanic Gardens, Kew: Potato season at Kew

History

73 The potato is native to the Peruvian-Bolivian Andes. Encyclopaedia Britannica: potato
74 Britannica says potatoes were domesticated by Indigenous peoples of the central Andes over 7,000 years ago, probably several times. Encyclopaedia Britannica: potato
75 Kew says the modern potato was cultivated around 8,500 years ago in what is now southern Peru. Royal Botanic Gardens, Kew: The plants of Peru
76 In the Andes, surplus potatoes were preserved as chuño, freeze-dried by the cold night temperatures and strong daytime sun. Encyclopaedia Britannica: potato
77 The Inca were among the Andean civilisations that grew potatoes, using terracing and irrigation. Encyclopaedia Britannica: potato
78 Spaniards introduced potatoes into Europe in the second half of the 16th century. Encyclopaedia Britannica: potato
79 Kew says potatoes arrived in Europe in the 1560s and were treated with suspicion, because their flower looks like that of poisonous deadly nightshade. Royal Botanic Gardens, Kew: Potato season at Kew
80 At first in Europe, potatoes were mainly used as animal food, and in northern Europe were grown in botanical gardens as an exotic novelty. Royal Botanic Gardens, Kew: Potato season at Kew
81 By the end of the 17th century the potato was a major crop in Ireland, and by the end of the 18th century in continental Europe and the west of England. Encyclopaedia Britannica: potato
82 The Great Famine in Ireland, 1845–49, happened when the potato crop failed in successive years because of late blight. Encyclopaedia Britannica: Great Famine (Irish history)
83 About 1 million people died in the Great Famine and perhaps 2 million more emigrated. Ireland’s population fell from almost 8.4 million in 1844 to 6.6 million by 1851. Encyclopaedia Britannica: Great Famine (Irish history)
84 Britannica says heavy reliance on just one or two high-yielding types of potato left Ireland vulnerable, because it reduced genetic variety. Encyclopaedia Britannica: Great Famine (Irish history)
85 In the First World War, Kew Palace lawn was dug up to grow vegetables for the Home Front, and the lawn alone produced 27 tonnes of potatoes. Royal Botanic Gardens, Kew: Kew Gardens in the First World War
86 In 1995 the potato became the first crop grown in space, aboard the Space Shuttle Columbia. Royal Botanic Gardens, Kew: Potato season at Kew
87 Kew grows the heritage variety Pink Fir Apple, which dates from 1850. Royal Botanic Gardens, Kew: Potato season at Kew
88 Kew says the heaviest potato ever grown weighed 4.98kg, grown in 2011 by an amateur gardener in Nottinghamshire. Royal Botanic Gardens, Kew: Potato season at Kew · checked 29 Oct 2026
89 The International Potato Center calls the potato the third most important food crop in the world after rice and wheat, in terms of human consumption. International Potato Center (CIP): Potato
90 The UN International Day of Potato is 30 May. In 2026 it was marked on 29 May, because 30 May fell on a Saturday. FAO / United Nations: International Day of Potato · checked 29 Oct 2026
91 2008 was the International Year of the Potato. FAO / United Nations: International Day of Potato

Where sources differ

92 The International Potato Center says there are over 4,000 edible varieties of potato, mostly in the Andes. Further down the same page it says more than 4,500 varieties of native potatoes. International Potato Center (CIP): Potato
93 Kew’s plants of Peru page says there are over 5,000 varieties of potatoes. Royal Botanic Gardens, Kew: The plants of Peru
94 Kew’s potato season page says there are over 100 different types of potato. Royal Botanic Gardens, Kew: Potato season at Kew
95 Garden Organic spacing: earlies and second earlies about 30cm apart in rows 50–60cm apart; maincrops 40cm apart in rows 70cm apart. Garden Organic: Potatoes growing guide
96 Garden Organic planting times: earlies mid- to late March, second earlies early to mid-April, maincrops mid- to late April. Garden Organic: Potatoes growing guide
97 Garden Organic says early varieties will be ready from June to July, around nine to ten weeks after planting. Garden Organic: Potatoes growing guide
98 Kew says first earlies take around 12 weeks to produce a crop, and second earlies around 13–16 weeks. Royal Botanic Gardens, Kew: Potato season at Kew
99 Garden Organic’s container guide says earlies are ready about 10–12 weeks after planting and maincrops after about 20 weeks. Garden Organic: Growing potatoes in containers (A12, PDF)
100 The RHS says to chit until the sprouts are about 5cm (2in) long. RHS: How to grow potatoes
101 Garden Organic says seed potatoes are ready for planting when they have 2cm shoots, in around four to six weeks. Garden Organic: It’s time to chit your potatoes!