Vegetablefruiting vegetableSome care needed

Tomato

Solanum lycopersicum

The crop most people start with and the one that most rewards getting the details right. A tomato is a frost-tender perennial from the Andes grown as an annual, which explains almost everything about how it behaves: it will not tolerate cold, it fruits continuously if allowed to, and in a British summer it is racing the season. Under cover it is straightforward. Outdoors it depends on the year — and on blight.

Position: Full sun
Water: high demand
Drainage: Moisture-retentive, Free-draining
Grows to: 150–200 cm × 45–60 cm
Hardiness: H1C
Harvest: July to October
Difficulty: Some care needed

Described view

A cordon tomato plant tied to a cane, showing the single main stem, a truss of ripening fruit and the pinched-out joints where side shoots were removed

August

Harvest

Tomato’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

Activity	F	M	A	M	J	A	S	O
Sow under cover	February.	March.
Plant out			April.	May.
Harvest					July.	August.	September.	October.

Names that cause confusion

Lycopersicon esculentum — The former botanical name, still widely printed on seed packets and in older books. It refers to this same plant; the genus was merged back into Solanum.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Sow under cover
6–8 weeks before your last spring frost
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Tomatoes — sowing
Checked 2026-08-13
Earlier than this and the plants outgrow the windowsill before it is safe to put them out.
Germination
5–8 weeks before your last spring frost, 7–14 days at 18–24 °C
source
Sourced guidancehigh confidence
- OSU Extension Service — Oregon State University: Seed germination temperatures
Checked 2026-08-13
Plant out
0–3 weeks after your last spring frost
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Tomatoes — planting out
Checked 2026-08-13
Wait for settled warmth rather than the date. A chilled young tomato never quite catches up.

Conditions it needs

Light: Full sun
Direct sun: 6–8 hours a day
Frost: Frost tender
Hardiness rating: H1c (RHS)
Survives down to: 10–12 °CSourced guidanceDepends on conditions
Grows best at: 18–27 °C
Germinates at: 18–24 °C
Soil: Loam, Peat-free compost
Soil pH: 5.5–7.5
Drainage: Moisture-retentive, Free-draining
Water needs: high
Drought: poor tolerance
Waterlogging: poor tolerance
Heat: moderate toleranceHorticultural consensusDepends on conditions
Wind and exposure: poor tolerance

Where these figures come from

LightSourced guidancehigh confidence

Royal Horticultural Society: Grow your own: tomatoes

Checked 2026-08-13

Direct sunSourced guidancehigh confidence

University of Minnesota Extension — University of Minnesota: Growing tomatoes in home gardens

Checked 2026-08-13

FrostSourced guidancehigh confidence

Royal Horticultural Society: Tomatoes — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancehigh confidence

Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Survives down toSourced guidanceDepends on conditionshigh confidence

Applies when: Growth stalls below roughly 10 °C rather than the plant dying; frost kills it outright at 0 °C.

Royal Horticultural Society: Tomatoes — growing

Checked 2026-08-13

Grows best atSourced guidancehigh confidence

University of Minnesota Extension — University of Minnesota: Growing tomatoes — temperature

Checked 2026-08-13

Germinates atSourced guidancehigh confidence

OSU Extension Service — Oregon State University: Vegetable seed germination temperatures

Checked 2026-08-13

SoilSourced guidancehigh confidence

Royal Horticultural Society: Tomatoes — soil

Checked 2026-08-13

Soil pHSourced guidancehigh confidence

University of Minnesota Extension — University of Minnesota: Soil pH for vegetable crops

Checked 2026-08-13

DrainageSourced guidancehigh confidence

Royal Horticultural Society: Tomatoes — soil

Checked 2026-08-13

Water needsSourced guidancehigh confidence

Royal Horticultural Society: Tomatoes — watering

Checked 2026-08-13

DroughtHorticultural consensusmoderate confidence

Royal Horticultural Society: Tomatoes — watering

Checked 2026-08-13

WaterloggingHorticultural consensusmoderate confidence

University of Minnesota Extension — University of Minnesota: Tomato — soil requirements

Checked 2026-08-13

HeatHorticultural consensusDepends on conditionsmoderate confidence

Applies when: Fruit set falls away above roughly 32 °C day or 24 °C night temperatures — a greenhouse problem in Britain rather than an outdoor one.

Home and Garden Information Center — Clemson Cooperative Extension: Tomato — fruit set and high temperature

Checked 2026-08-13

Wind and exposureHorticultural consensusmoderate confidence

Tall cordons snap in wind and need tying in; bush types are less exposed.

No external citation — see the evidence type above.

Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Tomato will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Works, with one condition	Tomato will crop on sandy, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Chalky and alkaline	Struggles here	Tomato struggles on chalky and alkaline: It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. It roots to about 45 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely.
Loam	Prefers this soil	Loam suits Tomato as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering. There is ample rooting depth for it.
Silty	Prefers this soil	Silty suits Tomato as it stands: The pH suits it: it wants 5.5 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering. There is ample rooting depth for it.
Peaty and acid	Works, with one condition	Tomato will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Struggles here	Tomato struggles on shallow over rock: It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. It roots to about 45 cm and this soil offers roughly 25 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely.
Made ground and urban soil	Struggles here	Tomato struggles on made ground and urban soil: It needs ground that drains, and this soil holds water. For a crop lifted before winter the risk is not rot but the season: waterlogged ground is cold and unworkable in spring, so sowing is late and germination patchy. It roots to about 45 cm and this soil offers roughly 30 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height: 150–200 cmSourced guidanceDepends on conditions
Mature spread: 45–60 cm
Rooting depth: 45–60 cm
Spacing: 45–60 cm apart
Row spacing: 75–90 cm

Where these figures come from

Mature heightSourced guidanceDepends on conditionshigh confidence

Applies when: Cordon (indeterminate) cultivars, which keep growing until stopped. Bush (determinate) cultivars reach roughly 45–75 cm and stop of their own accord.

Royal Horticultural Society: Tomatoes — cordon training

Checked 2026-08-13

Mature spreadHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Rooting depthHorticultural consensusmoderate confidence

USU Extension — Utah State University: Vegetable rooting depths

Checked 2026-08-13

SpacingSourced guidancehigh confidence

Royal Horticultural Society: Tomatoes — spacing

Checked 2026-08-13

Row spacingSourced guidancehigh confidence

University of Minnesota Extension — University of Minnesota: Growing tomatoes — spacing

Checked 2026-08-13

Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

In a container

Minimum volume: 20 litres or moreSourced guidanceDepends on conditions
Minimum depth: 25 cm

Where the container figures come from

Minimum volumeSourced guidanceDepends on conditionshigh confidence

Applies when: Per plant, for a cordon grown to full height. Bush and dwarf cultivars manage in 10–15 litres. The standard three-plants-per-grow-bag arrangement gives each plant well under this and is the reason grow-bag tomatoes need watering twice a day in hot weather.

Royal Horticultural Society: Growing tomatoes in containers

Checked 2026-08-13

Minimum depthHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Volume matters more than depth here: the constraint is water reserve, not rooting depth.

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

Method	Suitability	What it needs
Greenhouse	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Tomatoes under glass Checked 2026-08-13	Daily ventilation in summer; Support for cordon types to the roofThe reliable option in Britain: warmth, a longer season and rain kept off the leaves, which is most of the blight problem solved.
Polytunnel	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Tomatoes under cover Checked 2026-08-13	Ventilation at both ends
Container	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Growing tomatoes in containers Checked 2026-08-13	At least 20 litres per cordon plant; Watering once or twice daily in hot weather; A high-potassium feed once fruit has set
Raised bed	Well suited source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Sturdy support for cordons
Hydroponics	Well suited source Sourced guidancehigh confidence Purdue Extension — Purdue University: Greenhouse tomato production Checked 2026-08-13	Support to full height; Assistance with pollination where insects cannot reach the flowers
Open ground	Workable Sourced guidanceDepends on conditionshigh confidence Applies when: Depends on the season and the region. In southern Britain a bush cultivar in a warm sheltered spot crops well most years; in a wet summer blight can take the crop before it ripens, and in the north it is marginal. Royal Horticultural Society: Outdoor tomatoes Checked 2026-08-13	A sheltered sunny position; Preferably a blight-resistant cultivar
Grow tent	Workable source GrowingHQ editorial positionmoderate confidence Physically straightforward — the plant does not care where the light comes from — but a tomato needs a lot of light for a long time, and the running cost per fruit is high compared with a summer windowsill. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	High light output; Hand pollination
Aquaponics	Workable source Sourced guidancehigh confidence Purdue Extension — Purdue University: Aquaponic fruiting crops Checked 2026-08-13
Windowsill	Marginal source GrowingHQ editorial positionmoderate confidence Dwarf and micro cultivars will fruit on a bright sill; a standard cultivar will grow long and pale and set almost nothing. Rated for the dwarf case only. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	A dwarf or bush cultivar; A south-facing sill; Tapping the flowers to set fruit
Vertical growing	Not assessed Insufficient evidenceconfidence unknown No assessment of tomatoes in stacked vertical planters that GrowingHQ can stand behind. No external citation — see the evidence type above. Checked 2026-08-13

Growing it

SowingSow into moist seed compost, cover thinly, and keep at 18–24 °C until germination. Move to the brightest place available the moment the seedlings appear — a warm dark windowsill produces long weak seedlings within days.0.5–1 cm
TransplantingPot on into individual pots at the first true leaf. Tomatoes root from their stems, so a leggy seedling can be buried deeper than it was growing and will make roots along the buried section.
WateringWater steadily rather than heavily. Irregular watering is the direct cause of blossom end rot and of split fruit, and both are far commoner than any disease.
FeedingBegin a high-potassium tomato feed once the first truss has set fruit. Before that, feeding pushes leaf at the expense of flowers.
SupportTie cordon plants to a cane or string as they grow. A fruiting truss is heavy enough to break an unsupported stem.
TrainingOn cordon cultivars, pinch out the side shoots that form in the joint between leaf and main stem, and stop the plant after four or five trusses outdoors so the fruit it has set can ripen. Bush cultivars are not pinched at all — doing so removes the crop.
PollinationTomato flowers are self-fertile and set readily outdoors. Under glass with no wind or insects, tapping the supports daily while the flowers are open improves set.
ProtectionTomatoes are not overwintered in Britain. They are frost-tender and short-lived, and a plant kept going under cover through the winter crops poorly and carries pests into spring. What is worth protecting is the end of the season: cover outdoor plants with fleece when the first frost is forecast to gain a fortnight, and pick every remaining fruit before it — green tomatoes ripen indoors in a drawer with a banana, and frosted ones do not ripen at all.

Where this guidance comes from

SowingSourced guidancehigh confidence: Royal Horticultural Society: Tomatoes — sowing
Checked 2026-08-13
TransplantingSourced guidancehigh confidence: Royal Horticultural Society: Tomatoes — potting on
Checked 2026-08-13
WateringSourced guidancehigh confidence: Royal Horticultural Society: Tomatoes — watering
Checked 2026-08-13
FeedingSourced guidancehigh confidence: Royal Horticultural Society: Feeding tomatoes
Checked 2026-08-13
SupportSourced guidancehigh confidence: Royal Horticultural Society: Tomatoes — supporting
Checked 2026-08-13
TrainingSourced guidancehigh confidence: Royal Horticultural Society: Tomatoes — pinching out side shoots
Checked 2026-08-13
PollinationHorticultural consensusmoderate confidence: Royal Horticultural Society: Tomatoes under glass — pollination
Checked 2026-08-13
ProtectionSourced guidancemoderate confidence: Royal Horticultural Society: Tomatoes — end of season
Checked 2026-08-13

The bud you cut to becomes the new shoot, and it grows in the direction it points — which is why an outward-facing bud opens the plant up and an inward-facing one crosses the middle.

Is it worth putting under cover?

Whether it will grow there is on the methods table above. This is whether the space is well spent, which is a different question and usually the one being asked.

Structure	What protection is worth	What decides it
Greenhouse	Improves reliability source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Blight. Tomatoes crop perfectly well outdoors in a good year and lose the crop to late blight in a wet one, and a covered roof keeps the foliage dry enough to prevent infection.Daily ventilation in summer; Support for cordon typesDeliberately `improves` rather than `unlocks`, which is the entry most likely to be argued with. Outdoor tomatoes ripen in Britain most years — what protection buys is the year they otherwise would not.
Polytunnel	Improves reliability source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Blight, addressed identically. A tunnel is normally cropped in the ground, so soil-borne disease builds up under a rotation that never leaves cover. A greenhouse can sidestep it with pots or fresh growbags; a tunnel bed cannot. Tomatoes are the crop where tunnel soil sickness shows up first, because they are the crop people replant in the same bed every year.

Growing it without soil

Nearly anything can be grown in a soilless system by somebody with enough equipment. The useful question is whether it is worth it, in which technique, and what goes wrong.

Well suited

An established soilless crop. Grown this way commercially or routinely by home growers, with predictable results.

source

Sourced guidancehigh confidence

Purdue Extension — Purdue University: Greenhouse tomato production

Checked 2026-08-13

One of the most established protected soilless crops in the world. The barriers at home are light and support rather than horticulture.

Techniques that suit it

Drip-fed mediumSolution is dripped into an inert medium around each plant. The most forgiving technique and the one that suits large, long-season, heavy crops.
Ebb and flowA bed of inert medium floods and drains on a timer. The medium holds moisture between floods, which makes it far more tolerant of interruption than NFT.
Deep water cultureRoots hang in aerated solution. Very productive and very unforgiving of solution temperature — warm solution holds less oxygen and root disease follows.

Sourced guidanceDepends on conditionshigh confidence

Applies when: Drip-fed medium is the commercial standard: a long-season heavy crop needs a root volume and a buffer that nutrient film cannot provide.

Purdue Extension — Purdue University: Greenhouse tomato production

Checked 2026-08-13

Root space: Large. A cordon tomato carries a substantial root system for months, so bare-root channel systems are a poor fit and medium beds or large containers of inert substrate are the norm.
Support: Essential and substantial: strings or canes to two metres and above, taking the weight of a fully laden plant for months.
source
Sourced guidancehigh confidence
Royal Horticultural Society: Tomatoes — supporting
Checked 2026-08-13
Lighting: Fully lit by lampsHorticultural consensusDepends on conditions
Solution temperature: 18–22 °C
pH band: 5.5–6.5

Where these figures come from

Root spaceSourced guidancehigh confidence

Purdue Extension — Purdue University: Greenhouse tomato production

Checked 2026-08-13

LightingHorticultural consensusDepends on conditionsmoderate confidence

Applies when: In a greenhouse, daylight with supplementary winter lighting. In a closed indoor system a tomato is one of the most light-hungry crops there is, and the running cost per fruit is the real constraint.

No external citation — see the evidence type above.

Checked 2026-08-13

Solution temperatureSourced guidancemoderate confidence

Purdue Extension — Purdue University: Solution temperature and dissolved oxygen

Checked 2026-08-13

pH bandSourced guidancehigh confidence

Purdue Extension — Purdue University: Greenhouse tomato production

Checked 2026-08-13

What actually goes wrong

Blossom end rot. Irregular water availability prevents calcium reaching the fruit tip, and in a soilless system that is usually a scheduling or pH problem rather than a shortage in the solution.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Blossom end rot
Checked 2026-08-13
No pollination. Tomato flowers are self-fertile but need vibration to release pollen, and indoors nothing provides it.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Tomatoes under glass — pollination
Checked 2026-08-13
Pump or power failure. In nutrient film and aeroponics there is no reserve at the roots, so a crop can be lost within hours; medium-based systems hold moisture and are far more forgiving.
source
Sourced guidancehigh confidence
- Purdue Extension — Purdue University: Hydroponic system design — failure modes
Checked 2026-08-13

No nutrient recipes here

GrowingHQ records pH bands, which are measurable properties of nutrient availability, and deliberately records no EC or PPM targets and no mixing instructions. Published targets vary by cultivar, growth stage, water source and technique, and the figures that apply to your system are on the product you bought.

Harvesting

Time from sowing or planting: 16–20 weeks

Sourced guidanceDepends on conditionshigh confidence

Applies when: From sowing, for an early cultivar under cover. Outdoors and in a cool summer, longer.

Royal Horticultural Society: Tomatoes — timing

Checked 2026-08-13

When it is readyPick when the fruit has taken its full colour and gives very slightly to gentle pressure. Flavour continues to develop on the plant, so leaving fruit a day or two past first colour is worth it.
How to pick itTwist or snap at the knuckle in the fruit stalk, or cut with scissors on trusses that resist.
Keeping itKeep at room temperature, not in a refrigerator: below about 12 °C the flavour compounds degrade and do not recover. Unripe fruit at the end of the season ripens indoors alongside a banana or apple.

Where the harvest guidance comes from

When it is readySourced guidancehigh confidence: Royal Horticultural Society: Tomatoes — harvesting
Checked 2026-08-13
How to pick itHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Keeping itSourced guidancehigh confidence: University of Maryland Extension — University of Maryland: Harvesting and storing tomatoes
Checked 2026-08-13

Keep picking

Regular picking keeps this plant producing. Fruit or leaves left to mature signal it to slow down or stop.

What goes wrong

Problem	How often	Notes
Physiological leaf roll	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Natural fruit drop	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Blossom drop	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Late blight	common source Sourced guidancehigh confidence Royal Horticultural Society: Tomato blight Checked 2026-08-13	The reason outdoor tomatoes fail in wet British summers. Under cover the risk is much lower.
Blossom end rot	common source Sourced guidancehigh confidence Royal Horticultural Society: Blossom end rot Checked 2026-08-13	Almost always a watering problem, and almost always in containers or grow bags.
Magnesium deficiency	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Damping off	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	At the seedling stage under glass.
Aphids	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Fruit splitting	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Skins split after a heavy watering that follows a dry spell — the same mechanism as blossom end rot, at the other end of the fruit.
Poor fruit set	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Under glass in still air, or in a heatwave when pollen becomes unviable.

Start from what you can see

What to look for

Views that settle something a description cannot. Where the photograph has not been taken yet, the description of what it will show is here instead — which is the useful half of it either way.

Described view

A hand pinching out a side shoot from the joint between a tomato leaf stalk and the main stem

The side shoot forms in the angle between leaf and stem — this is the growth removed on cordon cultivars.

Grown with, grown after, grown instead

Every relationship states its mechanism. A pairing nobody can explain is a pairing nobody has checked, and it does not go in.

Same rotation groupPotato
Both are Solanaceae and both host Phytophthora infestans. Growing them close together, or in succession on the same ground, lets blight move from one to the other and builds soil-borne solanaceous problems.
source
Sourced guidancehigh confidence
Royal Horticultural Society: Crop rotation
Checked 2026-08-13
Shares a problem withSweet pepper
Both Solanaceae with the same requirement for warmth and the same susceptibility to blossom end rot under irregular watering, so a problem on one is usually about to appear on the other.
source
Horticultural consensusmoderate confidence
No external citation — see the evidence type above.
Checked 2026-08-13

Safety and edibility

Cats and dogsUsually a short upset stomach

Listed as harmful to cats or dogs

Tomato is listed as harmful if eaten. The leaves and stems contain glycoalkaloids; the ripe fruit does not, and is not a concern. Eating the foliage causes drooling, vomiting and lethargy. Green unripe fruit sits between the two and is best treated as foliage.

source

Sourced guidancehigh confidence

ASPCA Animal Poison Control Center — toxic and non-toxic plant list — American Society for the Prevention of Cruelty to Animals: Solanum lycopersicum — toxic plants list

Checked 2026-08-13

Affected parts: leaf, stem.

Which parts are ediblechildrenpets
The fruit is the only edible part. Tomato leaves and stems contain glycoalkaloids and are not food, despite occasionally being suggested as a herb substitute.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Potentially harmful garden plants
Checked 2026-08-13
Eat the fruit. Compost the foliage rather than cooking with it.

Sources for this page

GrowingHQ editorial synthesis · Home and Garden Information Center · OSU Extension Service · Purdue Extension · Royal Horticultural Society · University of Maryland Extension · University of Minnesota Extension · USU Extension

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-13.

If something is wrong with it

Dark sunken patch at the bottom of a fruit — 2 causes GrowingHQ holds for tomato
Flowers dropping without setting fruit — 3 causes GrowingHQ holds for tomato
Leaves rolling or curling inwards — 4 causes GrowingHQ holds for tomato
Sticky leaves, or a sticky surface below the plant — 3 causes GrowingHQ holds for tomato
Lower leaves turning yellow — 3 causes GrowingHQ holds for tomato

Something else? Work through it with the diagnostic tool.