The big facts page

124 tomato 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 Tomatoes are one of the most popular crops to grow. You can start them from seed indoors or buy young plants, then grow them outdoors or in a greenhouse, in pots or in the ground. RHS: How to grow tomatoes
2 Tomatoes grow particularly well in a greenhouse, usually giving an earlier and larger crop. Outdoors, these tender plants need a warm, sunny, sheltered site. RHS: How to grow tomatoes
3 Cordon (indeterminate) tomatoes are vigorous, very tall plants that need tall supports. Bush (determinate) tomatoes are naturally more compact, great for smaller spaces. RHS: How to grow tomatoes
4 Trailing types can even be grown in windowboxes and hanging baskets. The RHS calls these the easiest type to grow. RHS: How to grow tomatoes
5 Small-fruited varieties tend to be the easiest to grow, the fastest to fruit and the most prolific. RHS: How to grow tomatoes
6 Tomato colours range from traditional red to dark purple, pink, orange, yellow or green, and even striped. RHS: How to grow tomatoes
7 There are small round cherry tomatoes, long plum varieties, medium-sized salad tomatoes and huge, wrinkled beefsteaks. RHS: How to grow tomatoes
8 RHS Award of Garden Merit (AGM) varieties include ‘Sungold’ (cherry), ‘Shirley’ (salad), ‘Tigerella’ (red with orange stripes) and ‘Gold Nugget’ (a compact bush cherry). RHS: How to grow tomatoes · checked 30 Oct 2026
9 Grafted plants are generally more vigorous, giving earlier and larger crops and more disease resistance, but they cost more. RHS: How to grow tomatoes
10 RHS sowing times: late February to mid-March for a greenhouse crop, or late March to early April for plants that will grow outside. RHS: How to grow tomatoes
11 Tomato seeds need about 18°C (64°F) to germinate: use a heated propagator, or a warm windowsill with a clear plastic bag over the top. RHS: How to grow tomatoes
12 Seedlings usually appear within a fortnight. Then uncover them and give them as much light as possible, so they don’t grow thin and leggy. RHS: How to grow tomatoes
13 Once seedlings have a couple of true leaves, move them into their own pots. Hold each one by a leaf, not by the delicate stem. RHS: How to grow tomatoes
14 Plant tomatoes into their final position in early summer, once temperatures are reliably above 16°C (60°F). RHS: How to grow tomatoes
15 Plant tomatoes deeply, with the first leaves just above the soil: the buried part of the stem grows extra roots. RHS: How to grow tomatoes
16 Tomatoes are tender, so get them used to outdoor conditions (hardening off) before planting out. RHS: How to grow tomatoes
17 In containers, the RHS suggests one plant in a 30–45cm (12–18in) pot, or two in a standard growing bag. RHS: How to grow tomatoes
18 RHS spacing in the ground: 45–60cm (18–24in) apart, depending on how big the plants will grow. Check the seed packet for exact spacings. RHS: How to grow tomatoes
19 The RHS says not to grow tomatoes in the same bed in consecutive years, to stop diseases building up in the soil. RHS: How to grow tomatoes
20 Water regularly to keep the soil or compost evenly moist. Up-and-down moisture levels can cause splitting or blossom end rot. RHS: How to grow tomatoes
21 Plants in containers dry out quickly and may need watering every day in hot weather. Curling leaves can be a sign of a thirsty plant. RHS: How to grow tomatoes
22 RHS top tip: sink a 15cm (6in) pot into the ground beside each plant and water into it, so the water goes straight down to the roots. RHS: How to grow tomatoes
23 Feed plants in containers every 10–14 days with a high potassium liquid feed once the first fruits start to swell. RHS: How to grow tomatoes
24 In a greenhouse, open the vents so pollinating insects can reach the flowers. You can also gently tap or shake open flowers to help move the pollen. RHS: How to grow tomatoes
25 On cordon tomatoes, pinch out the side-shoots that sprout from the joint between each leaf and the main stem. Check each time you water. RHS: How to grow tomatoes
26 Bush tomatoes are more compact, and their side-shoots should be left to grow. RHS: How to grow tomatoes
27 Tomatoes don’t cling to supports by themselves, so they must be tied in, or wound round a string, by hand as they grow. RHS: How to grow tomatoes
28 When cordons reach the top of their support, or have set seven trusses indoors or four outdoors, remove the growing tip two leaves above the top truss. RHS: How to grow tomatoes
29 A truss is a cluster of flowers or fruit growing from the same point on a stem. The word is used a lot for tomatoes. RHS: How to grow tomatoes
30 Mulch plants in the ground or a greenhouse border with garden compost or well-rotted manure, leaving a gap round the base of the stem. RHS: How to grow tomatoes
31 Garden Organic says there are hundreds of varieties, and calls tomatoes a great crop for someone new to growing. Garden Organic: Tomatoes growing guide
32 Garden Organic: remove any yellowing leaves, and any leaves that shade the lower trusses of fruit. Garden Organic: Tomatoes growing guide
33 Garden Organic gives a germination time of 8–11 days. Garden Organic: Tomatoes growing guide
34 Garden Organic says tomatoes are one of the easiest crops to save seed from: most won’t cross-pollinate. Garden Organic: Tomatoes growing guide
35 For growing outdoors, Garden Organic suggests ‘Gardener’s Delight’ (small) and ‘Tigerella’ (medium). Garden Organic: How to grow card, Tomato, Outdoor (PDF) · checked 30 Oct 2026
36 For growing indoors, Garden Organic suggests ‘Yellow Pear’ (small), and ‘Alicante’ and ‘Ailsa Craig’ (medium). Garden Organic: How to grow card, Tomato, Indoor (PDF) · checked 30 Oct 2026
37 At the end of the season, Garden Organic suggests ripening green tomatoes indoors, or protecting plants from frost with horticultural fleece. Garden Organic: How to grow card, Tomato, Outdoor (PDF)
38 University of Minnesota Extension calls tomatoes the most popular homegrown vegetable. They need a long, frost-free season and full sun. University of Minnesota Extension: Growing tomatoes in home gardens
39 UMN: when buying plants, choose sturdy ones up to a foot tall, with stems at least as thick as a pencil. Don’t buy plants with spotted leaves. University of Minnesota Extension: Growing tomatoes in home gardens
40 UMN: bush (determinate) plants typically reach 24–30 inches, then stop growing, and all their fruit ripens within four to six weeks. Handy for a big batch at once. University of Minnesota Extension: Growing tomatoes in home gardens
41 UMN: most tomato varieties are vining (indeterminate). They need cages, stakes or trellises, and keep flowering and ripening fruit until the weather gets too cold. University of Minnesota Extension: Growing tomatoes in home gardens
42 UMN: a resistant variety won’t get the disease; a tolerant one will, but it spreads more slowly and is less serious. Seed catalogues use codes to show which is which. University of Minnesota Extension: Growing tomatoes in home gardens
43 UMN: allow two to three feet in all directions between vining plants. Bush types can go closer together. University of Minnesota Extension: Growing tomatoes in home gardens
44 UMN: plant outdoors after all danger of frost has passed and the soil has warmed. University of Minnesota Extension: Growing tomatoes in home gardens
45 UMN: for a sturdier plant, dig a trench three to four inches deep, lay the plant in it and bury the stem up to just below the lowest remaining leaves. University of Minnesota Extension: Growing tomatoes in home gardens
46 UMN: one inch of rain or watering a week is ideal. Avoid overhead sprinklers, because wet leaves are more prone to disease. University of Minnesota Extension: Growing tomatoes in home gardens
47 UMN: put in stakes, cages, spirals or trellises at planting time. University of Minnesota Extension: Growing tomatoes in home gardens

Picking and ripening

48 Tomatoes start to ripen from midsummer, depending on the variety, the weather and fruit size. Cherry tomatoes ripen faster than bigger fruits. RHS: How to grow tomatoes
49 Greenhouse plants usually start cropping earlier than outdoor ones and carry on for longer, well into autumn. RHS: How to grow tomatoes
50 Check plants every few days and pick tomatoes one at a time, stalk attached, as soon as they’re ripe and fully coloured. RHS: How to grow tomatoes
51 At the end of the season, ripen unripe tomatoes somewhere warm and dark, or in a drawer with a banana. RHS: How to grow tomatoes
52 Garden Organic: ripen green tomatoes indoors in a sunny spot or in a dark place next to a ripe banana. Green tomatoes also make great chutney. Garden Organic: Tomatoes growing guide
53 UMN: when frost threatens at the end of summer, pick all the fruit and bring it indoors. University of Minnesota Extension: Growing tomatoes in home gardens
54 UMN: tomatoes picked truly green will probably never ripen to a good flavour, but ones starting to turn white or pink should. Some gardeners look for a white star or streak on the bottom. University of Minnesota Extension: Growing tomatoes in home gardens
55 UMN: ripen unripe fruit at room temperature, one layer deep and not touching. Warmth matters more than light. University of Minnesota Extension: Growing tomatoes in home gardens
56 UMN: tomatoes are one of the easiest foods to can (bottle) at home. University of Minnesota Extension: Growing tomatoes in home gardens

Pests and problems (some dated)

57 Tomato blight attacks the leaves and fruit, causing rotting. It is most common in warm, wet weather. RHS: How to grow tomatoes
58 Tomatoes are prone to blight outdoors, but rarely get it in a greenhouse. RHS: How to grow tomatoes
59 The RHS says splitting and cracking in late summer is difficult to prevent, and links it to up-and-down moisture levels. RHS: How to grow tomatoes
60 Blossom end rot is a round patch, greenish brown to black, at the flower end of the fruit (the end furthest from the plant). It becomes sunken as it grows. RHS: Blossom end rot
61 Blossom end rot isn’t a pest or a disease: it is caused by poor growing conditions. RHS: Blossom end rot
62 It is caused by a lack of calcium in the fruit, but the RHS says soils very rarely lack calcium. The real problem is an irregular water supply. RHS: Blossom end rot
63 Plants in pots or growing bags are most at risk. Plants in border soil are less likely to be affected. RHS: Blossom end rot
64 Affected fruits can’t be saved, but steady moisture protects the next ones. In hot spells, watering twice a day is better than once with double the volume. RHS: Blossom end rot
65 The RHS says calcium sprays on the leaves don’t work, because the fruit doesn’t take up calcium that way. RHS: Blossom end rot
66 Garden Organic links blossom end rot to too little or irregular watering, and says it is most common when the first trusses are forming. Garden Organic: Tomatoes growing guide
67 Tomato leaf mould is a fungal disease, mostly of greenhouse tomatoes: yellow blotches on top of the leaf, with greyish-brown mould underneath. RHS: Tomato leaf mould
68 To prevent leaf mould: ventilate well, avoid wetting the leaves, try to stay below 21°C (70°F), and pick off infected leaves as soon as you see them. RHS: Tomato leaf mould
69 The RHS lists ‘Shirley’ and ‘Cumulus’ as resistant cultivars, though new strains of the fungus can break down resistance. RHS: Tomato leaf mould · checked 30 Oct 2026
70 Glasshouse whitefly are tiny sap-sucking insects, about 1.5mm long, that fly up in clouds when a plant is disturbed. Their sticky honeydew lets black sooty moulds grow. RHS: Glasshouse whitefly
71 An established control is a tiny parasitic wasp, Encarsia formosa. Whitefly young that it has parasitised turn black, so you can see it working. RHS: Glasshouse whitefly
72 Each female whitefly can lay more than 200 eggs, and at 21°C (70°F) the life cycle can take about three weeks. RHS: Glasshouse whitefly
73 Whitefly often arrive on new plants, so check new purchases. RHS: Glasshouse whitefly
74 In Minnesota, UMN Extension says early blight and Septoria leaf spot are common tomato diseases, while late blight doesn’t turn up every year. University of Minnesota Extension: Growing tomatoes in home gardens
75 Tomato hornworms are large caterpillars that feed on leaves and fruit. University of Minnesota Extension: Growing tomatoes in home gardens
76 UMN: you can still have a satisfactory crop even when plants and fruit show some disease and pest problems. University of Minnesota Extension: Growing tomatoes in home gardens
77 Britannica lists bacterial wilt, early blight, mosaic virus, Fusarium wilt, nematodes and tomato hornworms among tomato pests and diseases. Encyclopaedia Britannica: tomato

The plant

78 The tomato’s botanical name is Solanum lycopersicum. It belongs to the nightshade family, Solanaceae. Encyclopaedia Britannica: tomato
79 Kew says tomatoes are in the nightshade family, along with aubergines and peppers. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
80 Tomato flowers are yellow, about 2cm across, with five petals, and hang in clusters. Encyclopaedia Britannica: tomato
81 Botanically, tomato fruits are berries, from 1.5 to 7.5cm across or more. Each has at least two chambers of small seeds in jelly-like pulp. Encyclopaedia Britannica: tomato
82 Tomato leaves are hairy, strongly scented, made of many leaflets, and up to 45cm (18in) long. Encyclopaedia Britannica: tomato
83 Tomato plants are usually much branched, spreading 60–180cm (24–72in). Encyclopaedia Britannica: tomato
84 Tomatoes are usually red, scarlet or yellow (green and purple varieties exist too), and range from round to oval, long or pear-shaped. Encyclopaedia Britannica: tomato
85 Britannica says the roots and leaves of the tomato plant are poisonous. Encyclopaedia Britannica: tomato
86 Before cultivation, wild tomatoes were small, fragrant fruits about the size of a cherry tomato. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
87 The tiny currant tomato (Solanum pimpinellifolium) is a close relative. Breeders have used it to create pest- and disease-resistant varieties. Encyclopaedia Britannica: tomato
88 Kew says small, tumbling varieties can be grown in a hanging basket or a pot on a balcony. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
89 At Kew, tomatoes are sown in April with some artificial heat, and planted outdoors only once all chance of frost has passed. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
90 Tomatoes need warm weather and plenty of sun, so in cooler climates they are mostly grown in hothouses. Encyclopaedia Britannica: tomato
91 Kew’s Kitchen Garden has grown ‘Outdoor Girl’, which ripens in cooler temperatures, and ‘Black Russian’, originally from Russia, a dark red-black beefsteak. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019) · checked 30 Oct 2026

History

92 The wild tomato came from the Andes of South America, probably mainly Peru and Ecuador. Encyclopaedia Britannica: tomato
93 The tomato is thought to have been domesticated in Mexico, before Columbus. Encyclopaedia Britannica: tomato
94 The word tomato comes from tomatl, a word in Nahuatl, the Aztec language. Encyclopaedia Britannica: tomato
95 Kew: though it is thought of as an Italian essential, the tomato actually came from the Andes. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
96 The Spanish brought the tomato to Europe in the early 16th century. The Spanish and Italians seem to have been the first Europeans to eat it. Encyclopaedia Britannica: tomato
97 In France and northern Europe the tomato was first grown as an ornamental and treated with suspicion as food, because botanists saw it was related to deadly nightshade. Encyclopaedia Britannica: tomato
98 Italians called it pomodoro (“golden apple”), which has led to guesses that the first tomatoes Europeans saw were yellow. Encyclopaedia Britannica: tomato
99 It has been suggested that the French called it pomme d’amour (“love apple”). Some scholars think both names may come from pomme des Mours (“apple of the Moors”), a name for the aubergine. Encyclopaedia Britannica: tomato
100 Tomatoes reached North America from Europe. Encyclopaedia Britannica: tomato
101 Thomas Jefferson is known to have grown tomatoes at Monticello in 1781. Encyclopaedia Britannica: tomato
102 Tomatoes were eaten in Louisiana as early as 1812, but not in the north-eastern states until about 1835. Encyclopaedia Britannica: tomato
103 The tomato didn’t become widely popular in the United States until the early 20th century. Encyclopaedia Britannica: tomato
104 Tomatoes are now grown commercially all over the world. Encyclopaedia Britannica: tomato
105 Kew says commercial tomato growing began in the mid-19th century, and tomatoes are now one of the most widely grown fruits in the world. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
106 A large share of the world’s tomato crop is processed into canned tomatoes, juice, ketchup, purée and paste. Encyclopaedia Britannica: tomato

Fruit or vegetable? Nix v. Hedden (1893)

107 Kew calls the tomato “a salad hero that’s one of the world’s favourite fruits”. Royal Botanic Gardens, Kew: Tasty tomatoes (25 October 2019)
108 In Nix v. Hedden, decided on 10 May 1893, the US Supreme Court held that tomatoes are “vegetables” and not “fruit” under the Tariff Act of 3 March 1883. U.S. Reports, Nix v. Hedden, 149 U.S. 304 (1893), Library of Congress (PDF of the printed opinion)
109 It was about tax. The importers had brought tomatoes from the West Indies in spring 1886 and paid duty under protest: vegetables carried a 10 percent duty, while fruit was on the free list. Justia: Nix v. Hedden, 149 U.S. 304 (1893)
110 The case was brought on 4 February 1887 against Hedden, the collector of the port of New York, to get the duty back. Cornell Law School LII: Nix et al. v. Hedden, Collector
111 Both sides read out dictionary definitions from Webster’s, Worcester’s and the Imperial Dictionary. The court said dictionaries are aids to its memory and understanding, not evidence. Justia: Nix v. Hedden, 149 U.S. 304 (1893)
112 Two witnesses, each with 30 years in the fruit and vegetable trade, said the words had no special meaning in trade, different from the dictionaries. Justia: Nix v. Hedden, 149 U.S. 304 (1893)
113 Justice Gray, giving the court’s opinion, wrote: “Botanically speaking, tomatoes are the fruit of a vine, just as are cucumbers, squashes, beans and peas.” U.S. Reports, Nix v. Hedden, 149 U.S. 304 (1893), Library of Congress (PDF of the printed opinion)
114 But in everyday language, the court said, they are vegetables: usually served at dinner with the main part of the meal, and not, like fruits generally, as dessert. U.S. Reports, Nix v. Hedden, 149 U.S. 304 (1893), Library of Congress (PDF of the printed opinion)
115 The court compared it with an earlier attempt to class beans as seeds. U.S. Reports, Nix v. Hedden, 149 U.S. 304 (1893), Library of Congress (PDF of the printed opinion)
116 The lower court had directed a verdict for the collector, and the Supreme Court affirmed the judgment. The case is reported as Nix v. Hedden, 149 U.S. 304 (1893). Justia: Nix v. Hedden, 149 U.S. 304 (1893)

Where sources differ

117 Garden Organic: outdoors, harden plants off and plant them 30–45cm apart when the first flowers open. Garden Organic: Tomatoes growing guide
118 Garden Organic’s calendar: sow indoors March/April, plant out late April to early June, harvest July to October. Garden Organic: Tomatoes growing guide
119 Garden Organic: sow tomato seed 0.1cm deep in pots. Garden Organic: Tomatoes growing guide
120 UMN: sow seeds a quarter of an inch deep, and keep them at 75–85°F on a heating mat until the seedlings come up. University of Minnesota Extension: Growing tomatoes in home gardens
121 UMN: start seeds indoors five to six weeks before planting outside, which in most of Minnesota is mid-April. University of Minnesota Extension: Growing tomatoes in home gardens
122 UMN: choose a spot where tomatoes and their close relatives (such as peppers, eggplants and tomatillos) haven’t grown for the past three or four years. University of Minnesota Extension: Growing tomatoes in home gardens
123 Garden Organic’s indoor card gives about 12–16 weeks to harvest. Garden Organic: How to grow card, Tomato, Indoor (PDF)
124 Garden Organic’s outdoor card gives about 16–20 weeks to harvest. Garden Organic: How to grow card, Tomato, Outdoor (PDF)