How to Grow Pumpkins Canada

On this page
  1. Pumpkin (Cucurbita maxima)
  2. Regional Planting Calendar
  3. Quick Facts
  4. At a Glance
  5. Soil & Growing Conditions
  6. Growth Stages
  7. Harvest & Storage
  8. Diseases
  9. Pests
  10. Companion Planting
  11. Pollination
  12. Plan your Pumpkins planting
  13. Growing Pumpkin in another region
  14. Sources
  15. Frequently Asked Questions

In Canada, pumpkins go in the ground late April to late May.

Timing is the decision that matters most in Canada: there are 6 separate regional sowing windows, ranging from mid March in Pacific Coastal Mild to early June in Far North & Alpine.

The short answer

Plant
Late April to late May
Site
6+ hours of sun, soil pH 5.5–7.5
Biggest risk
Grey mould

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

Pumpkin (Cucurbita maxima)

Pumpkin plants sprawling over the ground with several yellow flowers open — “Cimai-p-pucani (Tamil- சீமைப்பூசனி) (3911965125)” by Dinesh Valke from Thane, India is licensed under CC BY-SA 2.0. Source: Wikimedia Commons

11 sources cited · Verified

Regional Planting Calendar

Region Sow
Central Continental derived late April to late May
Prairies & Short-Season Continental derived late May to mid June
Pacific Coastal Mild derived mid March to early April
Far North & Alpine derived early June to late June
Atlantic Maritime derived early May to late May
Inland Valleys & Southern Lakes derived late April to late May

Rows marked derived are interpolated between regions our sources do state, because no source we consulted gives a figure for that region specifically. They are deliberately wider to reflect that uncertainty.

Central Continental - detail & sources

DERIVED from this region's own frost normal, not quoted for the region. Plant when soils are 65°F (18°C) or after all frost danger has passed; with black plastic mulch and row covers, sowing can be brought forward 2-3 weeks before the last frost, which is what makes the crop finish on a short season. Applied to a mean last frost of 30 April (NOAA NCEI 1991-2020 for the USA; Environment and Climate Change Canada normals for Canada), that gives 30 April to 21 May. Your own local frost date is what matters — a region spans a range, and this figure comes from one representative station within it.

Prairies & Short-Season Continental - detail & sources

DERIVED from this region's own frost normal, not quoted for the region. Plant when soils are 65°F (18°C) or after all frost danger has passed; with black plastic mulch and row covers, sowing can be brought forward 2-3 weeks before the last frost, which is what makes the crop finish on a short season. Applied to a mean last frost of 21 May (NOAA NCEI 1991-2020 for the USA; Environment and Climate Change Canada normals for Canada), that gives 21 May to 11 June. Your own local frost date is what matters — a region spans a range, and this figure comes from one representative station within it.

Pacific Coastal Mild - detail & sources

DERIVED from this region's own frost normal, not quoted for the region. Plant when soils are 65°F (18°C) or after all frost danger has passed; with black plastic mulch and row covers, sowing can be brought forward 2-3 weeks before the last frost, which is what makes the crop finish on a short season. Applied to a mean last frost of 18 March (NOAA NCEI 1991-2020 for the USA; Environment and Climate Change Canada normals for Canada), that gives 18 March to 8 April. Your own local frost date is what matters — a region spans a range, and this figure comes from one representative station within it.

Far North & Alpine - detail & sources

DERIVED from this region's own frost normal, not quoted for the region. Plant when soils are 65°F (18°C) or after all frost danger has passed; with black plastic mulch and row covers, sowing can be brought forward 2-3 weeks before the last frost, which is what makes the crop finish on a short season. Applied to a mean last frost of 5 June (NOAA NCEI 1991-2020 for the USA; Environment and Climate Change Canada normals for Canada), that gives 5 June to 26 June. Your own local frost date is what matters — a region spans a range, and this figure comes from one representative station within it.

Atlantic Maritime - detail & sources

DERIVED from this region's own frost normal, not quoted for the region. Plant when soils are 65°F (18°C) or after all frost danger has passed; with black plastic mulch and row covers, sowing can be brought forward 2-3 weeks before the last frost, which is what makes the crop finish on a short season. Applied to a mean last frost of 7 May (NOAA NCEI 1991-2020 for the USA; Environment and Climate Change Canada normals for Canada), that gives 7 May to 28 May. Your own local frost date is what matters — a region spans a range, and this figure comes from one representative station within it.

Inland Valleys & Southern Lakes - detail & sources

DERIVED from this region's own frost normal, not quoted for the region. Plant when soils are 65°F (18°C) or after all frost danger has passed; with black plastic mulch and row covers, sowing can be brought forward 2-3 weeks before the last frost, which is what makes the crop finish on a short season. Applied to a mean last frost of 30 April (NOAA NCEI 1991-2020 for the USA; Environment and Climate Change Canada normals for Canada), that gives 30 April to 21 May. Your own local frost date is what matters — a region spans a range, and this figure comes from one representative station within it.

Quick Facts

Factor Value
Soil pH 5.5 - 7.5
Sunlight 6-10 hours direct sun
Germination temp 18°C
Optimal growing temp 20-30°C
Minimum survivable temp 9°C
Soil texture RHS: soil should be "fertile and moisture retentive but not waterlogged".
Drainage RHS: moisture-retentive but not waterlogged; a "warm sunny site" with "full sun, to aid ripening".
Lifecycle tender plants requiring a long, hot growing season
Edible parts fruits

At a Glance

Cucurbita maxima Pumpkin Grey mould Powdery mildew Cucumber mosaic virus Downy mildew (general) Bacterial wilt of cucur… Cercospora leaf spot Alternaria leaf blight Anthracnose Gummy stem blight Slugs Snails Glasshouse whitefly Glasshouse red spider m… Melon aphid (cotton aph… Pickleworm Squash bug Squash vine borer Striped cucumber beetle Spotted cucumber beetle Squash beetle DISEASES PESTS

Soil & Growing Conditions

Pumpkin vines covering the ground beside a pallet compost bay — “Calabazar” by Ayotte, Gilles, 1948- is licensed under CC BY-SA 4.0. Source: Wikimedia Commons
“Calabazar” by Ayotte, Gilles, 1948- is licensed under CC BY-SA 4.0. Source: Wikimedia Commons.

Water: RHS: pumpkins need "plenty of water, especially when fruiting"; use rainwater where possible and water early morning or evening. Utah State: "Water deeply and infrequently, 1-2 inches per week"; "Reduce watering amounts as the fruits ripen". Univ. of Maryland: "Water deeply and regularly at the base of each plant, especially during hot, dry weather and once fruits start to form".

Soil pH range

5.5 7.5

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

Growth Stages

Stage BBCH Notes
Sowing and germination 0 PLANTING DEPTH AND SPACING. Sow direct once soil reaches 65°F (18°C) or after all frost danger has passed — whichever is later. Seed goes 1–2 in (2.5–5 cm) deep, 4–6 seeds to a mound with mounds 4 ft (1.2 m) apart; thin to two plants per mound after emergence. Transplants go 2 ft apart in rows 4–6 ft apart. Utah State notes that with mulch and row covers seed or plants can be set out 2–3 weeks BEFORE the last frost, which is what lets a long-season squash finish where the season is short. Do not lay organic mulch until soil has reached 75°F — mulching cold ground keeps it cold.
Seedling establishment 1 Thin each mound to the two strongest seedlings. This is the stage cucumber beetles do disproportionate damage at, and where bacterial wilt infection takes hold, so if row cover is going on at all it goes on now — and must come off at flowering for pollination.
Vine growth 3 The plant builds the leaf area that will fund the fruit. Give it the room the spacing implies rather than crowding: airflow between plants is the main defence against the powdery and downy mildews that dominate this family, and Clemson notes powdery mildew favours dry weather with high humidity between 50 and 90°F — conditions growers often assume are safe.
Flowering 6 Utah State: "The first flowers are almost always male. Female flowers will have small fruits behind the flowers." That sequence alarms first-time growers every season and is entirely normal — there is nothing wrong with a plant producing only male flowers for the first week or two. Squash needs insects to move pollen between the two, so where bee activity is poor, hand pollination with a soft brush is the fix.
Fruit development 7 Winter squash takes 45–55 days to mature from flowering. Keep the fruit off wet soil where you can — a board or a bed of straw under a developing squash prevents the rot that follows prolonged ground contact.
Maturity and harvest 8 Utah State's test for winter squash is physical rather than visual: harvest "when the rind is hard and impervious to scratching from a fingernail". A squash cut before that point will not cure and will not store. Leave a few inches of stem attached — a squash snapped off at the shoulder rots from the wound.
Curing and storage 9 Cure, then store cool and dry at 50–55°F (10–13°C). This is the crop's whole point in a kitchen garden: properly cured and stored, it is one of the few vegetables that carries a garden through winter without a freezer.

Harvest & Storage

A person bending to harvest pumpkins in a large field — “Carantec - Ile Callot - Récolte de potimarrons 1” by Renhour48 is licensed under CC BY-SA 4.0. Source: Wikimedia Commons
“Carantec - Ile Callot - Récolte de potimarrons 1” by Renhour48 is licensed under CC BY-SA 4.0. Source: Wikimedia Commons.

When to pick: RHS: harvest when fruits are fully matured and have coloured up on the plant, cutting with "at least 10cm (4in) of stem still attached". RHS gives no time from sowing to harvest. Utah State: "Pumpkins are mature when they are fully colored, when the vine begins to die back, and when the rind is hard and impervious to scratching from a fingernail". Univ. of Maryland: "The rinds need to be hard and firm for pumpkins to store well", harvesting "in late September or October before heavy frosts".

Storage

RHS: cure by "laying them out in the sun for a week to 10 days" to harden the skins, then store in a well-ventilated space at "10-15°C (50-60°F)". Univ. of Maryland independently gives a storage temperature "between 50 and 55 degrees F" (10-12.8°C), sitting inside the RHS 10-15°C range.

Diseases

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

Botrytis cinerea

Soft brown fruit decay; Fuzzy grey-brown mould

RHS pumpkin guide names grey mould among pumpkin diseases.

RHS pumpkin guide names powdery mildew among pumpkin diseases.

Cucumber mosaic virus

Cucumber mosaic virus (CMV)

Covered by the RHS phrase "Cucumbers and other cucurbits"; pumpkin is Cucurbita maxima.

Downy mildew (general)
high

Small yellow areas on the upper leaf surface expanding and browning, with grey mould on the underside directly beneath. Favoured by moist conditions. Resistant varieties work; fungicides only work preventatively.

Bacterial wilt of cucurbits
high

Erwinia tracheiphila

Vines wilt severely then die fast. There is no chemical control once a plant is infected, and the bacterium overwinters inside the cucumber beetles rather than in your soil -- so this is a pest problem presenting as a…

Cercospora leaf spot
medium

Cercospora beticola

Dark spots with lighter centres and darker margins; centres may drop out and lesions merge into blight. Progresses fastest at 79-90°F, where new leaves can be infected every 7 to 10 days. Overwinters in crop debris and…

Alternaria leaf blight
medium

Alternaria dauci

Small circular tan spots enlarging past 1.5 inches with concentric rings and a bull's-eye appearance, followed by severe leaf drop. Driven by bright sunshine with frequent dew or rain at 60-90°F. Overwinters on plant…

Anthracnose
medium

Colletotrichum spp.

Sunken reddish-brown lesions with yellow halo (anthracnose)

Leaf spots beginning yellowish or water-soaked, turning brown to black with a shot-hole look; black, circular, sunken cankers on the fruit. Needs rainy, cool weather for several days. The fungus overwinters on old…

Gummy stem blight
high

Didymella bryoniae

Brown or tan leaf spots, and stem cankers weeping a brown gummy substance, with vines wilting mid-season. No resistant varieties exist, and it survives on debris year to year -- so clearing debris and rotating to a…

Pests

Slugs

Gastropoda (slugs, various spp.)

RHS pumpkin guide lists slugs and snails among pumpkin pests.

Snails

Gastropoda (snails, various spp.)

RHS pumpkin guide lists slugs and snails among pumpkin pests.

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

Trialeurodes vaporariorum

Tiny white sap-feeders in groups on leaf undersides; the honeydew grows sooty mould that cuts photosynthesis and yield, and they vector numerous viruses. Reflective mulches are effective, and beneficial insects do much…

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)
medium

Tetranychus urticae

Pale yellow and reddish-brown stippling on the upper leaf surfaces, developing very fast and able to kill or badly stunt plants. Hard to spot until there are hundreds per leaf. Severe outbreaks are linked to…

Melon aphid (cotton aphid)
medium

Aphis gossypii

Found chiefly on leaf undersides, sucking sap and reducing both quality and quantity of fruit; infested leaves curl downward and may brown and die. Usually arrives once vines start to run. Transmits cucumber mosaic…

Pickleworm
medium

Diaphania nitidalis

Caterpillars tunnel into flowers, buds, stems and fruit, with sawdust-like frass protruding from small holes; damaged fruit often cannot be identified until it is cut open. It cannot survive winter in the Carolinas --…

Squash bug
high

Anasa tristis

A sap feeder that frequently kills squash plants outright; leaves wilt rapidly and go brittle. Adults overwinter unmated in sheltered places and appear slowly in spring, laying brick-red egg clusters as the vines begin…

Squash vine borer
high

Melittia cucurbitae

Where it occurs, larvae tunnel into the stems and often kill the plant when they feed in the basal part of the vine; the signs are a vine wilting suddenly and sawdust-like frass coming from holes in the stem. It…

Striped cucumber beetle
high

Acalymma vittatum

Where it occurs it is a yellow beetle about a fifth of an inch long with three black stripes, feeding on every part of the plant from emergence; the real damage is that it transmits bacterial wilt, which overwinters…

Spotted cucumber beetle
high

Diabrotica undecimpunctata howardi

Where it occurs it begins feeding as soon as plants emerge and either kills them outright or badly slows growth, and the larvae bore into roots and stems; it also transmits bacterial wilt. It cannot overwinter in the…

Squash beetle

Epilachna borealis

A US pest, one of only two plant-eating ladybugs in the country, resembling a large spotted ladybird. Overwinters as an adult in crop debris and feeds on cucurbit leaves; not a UK or Canadian concern.

Companion Planting

beneficial

Zea mays

Part of the "Three Sisters" polyculture: the sprawling pumpkin foliage shades the soil, suppressing weeds and conserving moisture beneath the taller sweetcorn.

Pollination

Honeybees Apis mellifera

RHS: insect pollination, mainly by honeybees; cold or poor weather reduces their activity and causes fruitlets to abort or rot at the flower end. Hand-pollination method as for courgette -- strip the petals from a male flower and press it into the female flowers.

Plan your Pumpkins planting

When to sow and plant Pumpkins depends on your own frost dates. Check the Canada vegetable planting calendar, or the month-by-month guides that cover Pumpkins: October. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.

Growing Pumpkin 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 11 sources behind this guide (Clemson Cooperative Extension, FAO EcoCrop, Garden Organic and others) is in the references of our UK guide to pumpkins; they describe the plant itself, which is the same wherever it grows.

Frequently Asked Questions

When should I sow pumpkins in Canada?

In Pacific Coastal Mild, from mid March. In Far North & Alpine, wait until early June. Treat these as a guide rather than a fixed date — the governing rule is to sow only once frost risk has passed and temperatures are reliably warm enough.

When do I sow pumpkins?

Sow mid March to late June, at around 18°C for germination.

What soil pH do pumpkins need?

A pH of about 5.5–7.5. 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 pumpkins?

Our data links 9 diseases and 11 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.

Get the Canada Garden Planner →

Instant PDF download · Written for Canadian growing conditions

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.

Vegetable Growing Guides Canada

Last verified 2026-08-06

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