How to Grow Tomatoes in Canada

On this page
  1. Tomato (Solanum lycopersicum)
  2. Quick Facts
  3. At a Glance
  4. Diseases
  5. Pests
  6. Nutrient Issues
  7. Soil & Growing Conditions
  8. Growth Stages
  9. Harvest & Storage
  10. Companion Planting
  11. Pollination
  12. Sowing, Planting Out & Care
  13. Fruit Disorders to Watch For
  14. Recommended Tools & Supplies
  15. Plan your Tomatoes planting
  16. Growing Tomato in another region
  17. Sources
  18. Frequently Asked Questions

Tomatoes are frost-tender and shouldn't be transplanted outdoors until temperatures reliably stay above 16°C.

The short answer

Ready in
52–90 days after planting out
Site
6+ hours of sun, soil pH 5.8–6.8
Biggest risk
Late blight

Core growing advice on this page is checked against named horticultural sources — see References.

Tomato (Solanum lycopersicum)

Ripe and ripening cherry tomatoes on the vine. Photo: Luigi Chiesa, CC BY-SA 3.0, via Wikimedia Commons.

29 sources cited · Verified

Quick Facts

Factor Value
Soil pH 5.8 - 6.8
Sunlight 6-8 hours direct sun
Germination temp 18°C
Optimal growing temp 21.1-26.7°C
Minimum survivable temp 5°C
Time to harvest 52-90 days after planting out
Soil texture clay, loam, sand
Drainage moist but well-drained
Soil organic matter 5% target
Lifecycle Tender perennial: persists and fruits for multiple years in frost-free climates (USDA zones 10-11), but is frost-sensitive and physiologically halted by freezing temperatures, so it is cultivated as an annual throughout temperate regions including the UK. This is a cultivation-practice adaptation, not the plant's underlying botanical lifecycle.
Edible parts fruit
Documented problems 7 diseases, 4 pests, 3 nutrient issues

At a Glance

Solanum lycopersicum Tomato Grey mould Verticillium wilt Cucumber mosaic virus Late blight (potato bli… Powdery scab Tomato spotted wilt Honey fungus Glasshouse red spider m… Glasshouse whitefly Western flower thrips Tomato moth (bright-lin… DISEASES PESTS

Diseases

Fuzzy grey-brown Botrytis mould covering a tomato stem — Rasbak, CC BY-SA 3.0
Rasbak, CC BY-SA 3.0
Grey mould
common

Botrytis cinerea

Soft brown fruit decay; Fuzzy grey-brown mould

RHS: tomato "may be susceptible to... grey moulds under glass" (Red Cherry cultivar page); RHS grey mould disease page independently lists tomatoes among commonly affected crops.

Verticillium wilt
high

Verticillium dahliae

Verticillium wilt now links tomato and strawberry -- second disease (after Damping-off/Grey mould) proven reusable across both flagship crops.

Cucumber mosaic virus

Cucumber mosaic virus (CMV)

UC IPM names tomato among CMV hosts: "cucurbits (except watermelon), tomato, spinach, celery, safflower, beans, blackeyes, peppers, beets, potatoes, many ornamentals and weeds". The RHS page did not list tomato.

Tomato leaf with brown late blight lesions — Scot Nelson, CC BY-SA 2.0
Scot Nelson, CC BY-SA 2.0

Phytophthora infestans

Rapidly spreading watery rot with pale leaf-edge sporulation (late blight pattern)

Retroactively linking tomato (already in graph) to the same Late blight disease entity now that potato -- the other major host -- has been added. RHS/UMN both confirm Phytophthora infestans is the identical pathogen…

Powdery scab
minor

Spongospora subterranea

Raised or sunken scabby patches on tuber/root skin

RHS: powdery scab "sometimes infects the roots of tomato plants" -- second cross-crop (potato/tomato) disease link established this session, alongside Late blight.

Tomato spotted wilt
moderate

Tomato spotted wilt virus (TSWV)

RHS Red Cherry cultivar page lists tomato spotted wilt virus among diseases tomato may be susceptible to.

Honey fungus
rare

Armillaria spp.

RHS Red Cherry cultivar page explicitly notes tomato is susceptible only "rarely".

Pests

Two-spotted red spider mite with silk threads, magnified — Gilles San Martin, CC BY-SA 2.0
Gilles San Martin, CC BY-SA 2.0
Glasshouse red spider mite (two-spotted spider mite)
moderate_to_severe

Tetranychus urticae

RHS explicitly names tomato among confirmed host plants for glasshouse red spider mite. Source: RHS, "Glasshouse red spider mite,".

Glasshouse whitefly adult on a leaf — Sanja565658, CC BY-SA 3.0
Sanja565658, CC BY-SA 3.0
Glasshouse whitefly
common

Trialeurodes vaporariorum

RHS Red Cherry cultivar page: susceptible to glasshouse whitefly

Western flower thrips
variable_regional

Frankliniella occidentalis

Vector of Tomato spotted wilt virus; also a direct feeding pest independent of virus transmission.

Tomato moth (bright-line brown-eye)
common

Lacanobia oleracea

RHS Red Cherry cultivar page: susceptible to tomato moth

Nutrient Issues

Calcium (Ca)

deficiency (physiological, uptake-related)

Blossom end rot

Correction

Not typically corrected by adding soil calcium alone -- driven mainly by irregular/insufficient watering restricting calcium transport to fruit; consistent watering is the primary corrective measure. Excess nitrogen and temperature fluctuation are contributing factors.

Magnesium (Mg)

deficiency

Interveinal chlorosis (older leaves)

Correction

RHS lists magnesium deficiency among tomato problems; standard correction is a magnesium supplement (e.g. Epsom salts foliar feed), though the specific corrective product was not independently verified this session.

Phosphorus (P)

deficiency

Correction

RHS names tomatoes among plants affected by phosphorus deficiency: "Stunted growth with purple discolouration on older leaves. Eventually, leaves turn dull yellow", especially in tender plants at low temperatures. Shortage is uncommon; very acidic or alkaline soils reduce availability and waterlogging hinders root uptake. Correction: improve drainage with organic matter, delay planting tender crops until late May or early June, and use fish, blood and bone.

Soil & Growing Conditions

Young Moneymaker tomato plant growing in a terracotta pot — Photo: Kolforn, CC BY-SA 4.0, via Wikimedia Commons.
Photo: Kolforn, CC BY-SA 4.0, via Wikimedia Commons.

Water: About 1 to 1.5 inches (25-38mm) of water per week (Ohio State Extension). Keep soil or compost evenly moist; container plants may need daily watering in hot weather (RHS).

Humidity: 60-70% RH is optimal for pollination (Alabama Cooperative Extension). Above ~80% RH pollen grains clump and pollination drops.

Soil pH range

5.8 6.8

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Growth Stages

  1. Establishment
  2. Vegetative Growth
  3. Flowering: Cordon types: side shoots removed as they appear; pinch growing tip after 7 trusses under cover or 4 outdoors (RHS).
  4. Fruit Development
  5. Ripening / Harvest: Killed by frost; cycle ends at first frost in UK outdoor/unheated conditions (tender perennial grown as annual).
  6. Senescence / Dormancy: End-of-season unripe fruit can be lifted and ripened off the vine (RHS).

Harvest & Storage

Ripe and ripening cherry tomatoes on the vine — Photo: Luigi Chiesa, CC BY-SA 3.0, via Wikimedia Commons.
Photo: Luigi Chiesa, CC BY-SA 3.0, via Wikimedia Commons.

When to pick: Tomatoes begin ripening from mid-summer; timing depends on variety, weather and fruit size (smaller cherry types ripen faster; greenhouse plants crop earlier and longer than outdoor). Check plants every few days and pick individually with the stalk attached as soon as fruit is ripe and fully coloured. At end of season, lift outdoor plants with unripe fruit and ripen on straw under cloches, or pick and ripen indoors in a warm dark place (e.g. a drawer with a banana).

Storage

Mature-green fruit: store at 55-70°F (12.8-21.1°C), 90-95% relative humidity, for 1-3 weeks. Firm-ripe fruit: same conditions but only 4-7 days (University of Maine Extension Bulletin #4135). Do not refrigerate unripe tomatoes - refrigeration inhibits ripening; ripen at about 70°F (21°C) instead, and refrigerating ripe fruit can reduce flavour and cause mealy texture (Clemson HGIC).

Companion Planting

Orange Tagetes erecta marigold flower in bloom — Usmonov Gayrat, CC0
Usmonov Gayrat, CC0
French/Aztec marigold
pest deterrent

Tagetes erecta

Airborne limonene emitted by marigolds gives a negative behavioural response in glasshouse whitefly; season-long companion planting significantly slows whitefly population development on tomato (PLOS ONE glasshouse trial, 48-day infestation period).

pest deterrent

Ocimum basilicum

Basil is a non-host plant for glasshouse whitefly; interplanting reduced proportion of marigolds with basil (plus nasturtium and Chinese cabbage) was also shown to reduce whitefly populations on tomato.

Strawberry plant in the ground with ripening fruit — Famartin, CC BY-SA 4.0
Famartin, CC BY-SA 4.0
avoid shared disease

Fragaria x ananassa

Not a beneficial pairing -- this is a warning. Avoid planting strawberries in ground recently occupied by tomatoes, or the reverse, because both are highly susceptible to Verticillium wilt. RHS UK Advisory Service case records name both Fragaria and Solanum among the most frequently diagnosed…

Potato seedling and harvested tubers — Scott Bauer, USDA-ARS, public domain
Scott Bauer, USDA-ARS, public domain
avoid shared disease

Solanum tuberosum

Reuses the existing avoid_shared_disease relationship type (already used elsewhere in the graph). Sources: RHS potato-blight, RHS tomato-blight, RHS potato cyst nematodes, RHS potato-scabs.

avoid shared disease

Solanum melongena

Clemson HGIC gives a three-year solanaceous rotation for eggplant twice over: for bacterial wilt, "do not plant eggplant in areas that have had tomatoes, Irish potatoes, or eggplant planted in the previous three years"; and for southern blight, "avoid planting in areas where tomatoes, peppers,…

Pollination

Tomato flower showing its yellow anther cone, beside a young developing fruit — The yellow anther cone is what a bumblebee vibrates to release pollen. Photo: Earth100, CC BY-SA 3.0, via Wikimedia Commons.
The yellow anther cone is what a bumblebee vibrates to release pollen. Photo: Earth100, CC BY-SA 3.0, via Wikimedia Commons.

Bumblebees (buzz pollinators) Bombus spp. (esp. B. terrestris, B. impatiens)

Tomato flowers are self-fertile and offer only pollen (no nectar reward). Outdoors, wind/vibration can trigger self-pollination; in the still air of a glasshouse this does not occur, so ~95% of commercial bumble bee colonies globally are used specifically in tomato greenhouses for buzz pollination (vibrating thoracic muscles to dislodge pollen). Bee pollination increases fruit set, yield and weight vs. other methods; honey bees cannot buzz-pollinate and do not reliably visit tomato flowers.

Sowing, Planting Out & Care

Sowing

  1. Fill modules or small pots with good quality seed compost.
  2. Sow 2 seeds per cell at 1cm depth, thinning to the strongest seedling.
  3. Keep warm at 18–22°C for germination (7–14 days).
  4. Pot on when roots fill the module, into 7.5cm then 10cm pots.
  5. Keep in bright light to prevent leggy growth.

Planting out and ongoing care

  • Harden off gradually over 7–10 days before planting outside.
  • Deep planting: bury the stem up to the first set of true leaves to encourage additional roots.
  • Support: stake cordon varieties at planting; tie in regularly as they grow.
  • Side shooting: remove side shoots on cordon (indeterminate) varieties weekly. Leave bush varieties unpruned.
  • Feeding: begin weekly high-potassium liquid tomato feed once the first flowers appear; containers every 10–14 days once fruits swell.
  • Watering: water consistently — irregular watering causes blossom end rot and splitting.
  • Pinch out the growing tip in late summer to direct energy into ripening existing fruit.

Fruit Disorders to Watch For

These are physiological disorders rather than diseases: they are caused by growing conditions, not by a pathogen, so no spray will fix them and nothing is passed between plants.

  • Splitting. Heavy rain after a dry spell causes fruits to split. Keep soil moisture even and harvest ripe fruits promptly.
  • Greenback. A hard green patch at the top of the fruit, caused by excess sun or potassium deficiency. Choose resistant varieties and feed regularly.
  • Blossom end rot. A dark, sunken patch at the base of the fruit — a calcium-transport problem driven by irregular watering, not a disease. See the Nutrient Issues section above.

Having the right tools makes growing tomatoes easier. Our hand tools for gardening include precision secateurs ideal for removing side shoots and harvesting fruit, and the soil and plant care range covers everything from propagators to high-potassium feeds.

Planning the wider plot? See the UK vegetable planting calendar, or the monthly guides for March, April and May.

Plan your Tomatoes planting

When to sow and plant Tomatoes depends on your own frost dates. Check the Canada vegetable planting calendar, or the month-by-month guides that cover Tomatoes: January, February, March, April, May, June, July, August, September, October. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.

Growing Tomato in another region

Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.

Sources

The full list of 29 sources behind this guide (Alabama Cooperative Extension System, Clemson Cooperative Extension, Global Biodiversity Information Facility (GBIF) and others) is in the references of our UK guide to tomatoes; they describe the plant itself, which is the same wherever it grows.

Frequently Asked Questions

How long do tomatoes take to grow?

Typically 52–90 days after planting out, depending on cultivar and growing conditions.

What soil pH do tomatoes need?

A pH of about 5.8–6.8. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.

What problems affect tomatoes?

Our data links 7 diseases and 4 pests to this crop. See the sections above for each one and how to manage it.

Plan next season before the problems start

Short-season growing is arithmetic before it is technique: days to maturity against frost-free days decides what will finish at all. The Canada Garden Planner does that subtraction for your region before you sow.

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SoilCommander Editorial Team — under the direction of Nitin Sharma, Co-Founder

Every growing guide is checked against RHS, USDA Cooperative Extension, and other named horticultural authorities before publishing.

How this guide is put together

The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against Canadian hardiness-zone and frost-date data, with provincial agriculture and university extension sources cited directly where one exists for a crop. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.

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Last verified 2026-09-02

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