How to Grow Pumpkins
On this page
Sow pumpkins once soil temperature reaches 18°C.
The short answer
- 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)
11 sources cited · Verified
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 |
| Documented problems | 9 diseases, 11 pests |
At a Glance
Diseases
Pests
Soil & Growing Conditions
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
Companion Planting
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
Timing for Pumpkins follows soil temperature and frost, not the calendar date. The Global vegetable planting calendar explains the method. 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
These 2 sources are specific to this region. 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
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
This page gives you the thresholds; the planner turns them into your own calendar. It works from what you can observe and measure in your garden rather than from dates written for somebody else’s latitude.
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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 international horticultural research and extension sources. 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.
Related Problem Guides
Last verified 2026-08-06
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Keep going
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.