Overview
What pumpkins need, when they crop, and whether you have room for them.
Pumpkins are tender, hungry, sprawling plants that need warmth, sun, rich soil and plenty of water. Give them a long frost-free season and room to run, and each plant rewards you with fruit for carving, soup or winter storage. The key is letting the fruit ripen fully and curing its skin in the sun before storing.
Quick facts
- Botanical name
- Cucurbita pepo, C. maxima
- Soil pH
- 5.8 – 6.6
- Feeding
- Heavy feeder
- Temperature
- 18 – 35 °C
- Hardiness
- Any zone, as an annual
- Time to harvest
- 90 – 120 days
- Propagation
- Seed
Optimal growth
Killed by frost
Growing details
- Germination
- 7 – 10 days
- Spacing
- 150 cm (59 in)
- Sowing depth
- 25 mm (1 in)
- Frost sensitivity
- Frost tender
Growing calendar
- Start indoors: April, May
- Sow outdoors: May, June, July
- Plant out: May, June
- Harvest: September, October
Mid- to late April in the UK, about three to four weeks before planting out (RHS, UMD). After the last frost, into warm soil; for Halloween, late May in the north to early July in the far south (Illinois). Late May or early June, once frost has passed (RHS). When fully coloured with a hard rind, before the first frost.
Is this plant right for you?
- Needs lots of space
- Frost tender
- Hungry and thirsty
- Stores for months
- Fun with children
- Needs bees
- Long season
Good to know
It is a hungry plant, so feed it regularly right through the growing season. Wait until the last frost has passed before it goes outside.
Before You Grow
Pick a size and habit that fits your space, and prepare a warm, sunny, rich planting site.
Even compact bush varieties reach about 90 cm (3 ft) across (RHS).
What you need
Seed or young plants
Chosen for size and space. See choose your pumpkins.
Small pots and warmth
A warm, bright windowsill or propagator. See sowing.
Space and sun
At least 90 cm (3 ft) per plant. See where pumpkins grow best.
Compost or manure
Plenty, for rich soil. See soil.
A cane and a sunken pot
To find and water the centre of each plant. See watering.
Tiles or straw
To keep fruits off damp soil. See training.
Choose your pumpkins
Choose by what you want the fruit for and how much space you have (RHS).
Small and pie pumpkins are best for cooking: sweeter, finer flesh. Minis such as ‘Jack Be Little’ and ‘Baby Bear’ weigh 0.2 to 0.7 kg (½ to 1½ lb) (Utah State).
Carving pumpkins are the classic large orange Halloween fruit: ‘Connecticut Field’, ‘Autumn Gold’ (Utah State); RHS-recommended ‘Cargo’ at 6 to 10 kg and ‘Charmant’ at 6 to 8 kg, with some resistance to powdery mildew.
Giants such as ‘Atlantic Giant’, ‘Big Max’ and ‘Big Moon’ can pass 45 kg (100 lb) with the right care. See growing a big pumpkin.
Bush or trailing. Trailing varieties spread several metres; bush types stay more compact, though still take at least a square metre (RHS).
Pumpkin or squash? The names overlap: both come from the same Cucurbita species, and "pumpkin" mostly means orange (Illinois).
Pumpkin sizes compared
-
Miniature
- Fruit weight
- 0.2 to 0.7 kg (½ to 1½ lb)
- Use
- Decoration, children
- Examples
- ‘Jack Be Little’, ‘Baby Bear’
-
Pie or sugar
- Fruit weight
- Small to medium
- Use
- Cooking
- Examples
- Sweet, close-grained flesh
-
Medium carving
- Fruit weight
- 4 to 10 kg (8 to 22 lb)
- Use
- Carving; ‘Lumina’ for painting
- Examples
- ‘Cargo’, ‘Charmant’, ‘Lumina’ (white)
-
Large carving
- Fruit weight
- 8 to 11 kg (18 to 25 lb)
- Use
- Carving
- Examples
- ‘Connecticut Field’, ‘Autumn Gold’
-
Giant
- Fruit weight
- 45 kg (100 lb) and more
- Use
- Shows
- Examples
- ‘Atlantic Giant’, ‘Big Max’
Weights from the RHS and Utah State. For a small garden, a miniature or bush variety.
Where pumpkins grow best
Pumpkins are a very tender warm-season crop (Illinois, UMD).
Site. Warm, sunny and sheltered from cold winds; pumpkins do less well in cool sites (RHS). At least six hours of direct sun, better eight to ten (UMD).
Temperature. They grow best between 18 and 35 °C (65 and 95 °F); below 10 °C (50 °F) growth slows and plants are injured even by a slight frost (Penn State).
Space. Bush plants 90 cm (3 ft) apart, trailing plants 1.5 m (5 ft) (RHS). Vining types need 5 to 9 m² (50 to 100 sq ft) per hill (Illinois).
Season. Most need more than 100 days to ripen (UMD).
- Best growth
- 18 to 35 °C (65 to 95 °F)
- Sun
- At least 6 hours; 8 to 10 is better
- Space per plant
- 90 cm to 1.5 m (3 to 5 ft)
Soil
Pumpkins are hungry: they need fertile, moisture-retentive soil that doesn’t waterlog (RHS).
Planting pits. For each plant, dig a hole about 30 cm (1 ft) wide and deep and fill it with a mix of soil and compost or well-rotted manure, then sow or plant into the mound (RHS).
Fertiliser. A general fertiliser before planting, following a soil test if you have one (Utah State, UMD).
pH. 5.8 to 6.6 (Penn State).
Drainage. Well-drained soil that still holds water. On sandy soil, plan to irrigate (Penn State).
Planting
Sow in warmth, then plant out once frost has passed and the soil has warmed.
Seed germinates poorly in cold soil: wait until it reaches at least 16 °C (60 °F) (Penn State, Illinois).
When to sow and plant pumpkins
Pumpkins can’t go outdoors until all danger of frost has passed and the soil has warmed (Illinois).
Indoors. Mid- to late April in the UK (RHS), about three to four weeks before planting out (UMD). Indoor sowing gives more reliable results, especially in colder areas.
Planting out. Late May or early June, after the last frost (RHS, Gardeners’ World).
Direct sowing. Late May or early June in the UK (RHS), once soil reaches 16 to 18 °C (60 to 65 °F) (Penn State, Utah State).
Timing for Halloween. Illinois sows from late May in the north to early July in the far south: planted too early, pumpkins may soften and rot before the end of October.
- Indoors mid- to late April.
- Out after the last frost.
- Soil at least 16 °C (60 °F).
How to sow pumpkins
Indoors in small pots for a head start, or direct where they’ll grow.
-
Soak (optional)
Overnight in water to speed germination (Gardeners’ World).
-
Sow on edge
One seed per 7.5 cm (3 in) pot, on its side, 1 cm (⅜ in) deep, so water doesn’t sit on the flat seed (RHS); Gardeners’ World sows two per 8 cm pot and keeps the stronger.
-
Keep warm
At 18 to 21 °C (65 to 70 °F), in a propagator or on a warm windowsill under a clear bag (RHS). Seedlings appear in 7 to 10 days (UMD).
-
Pot on
Into slightly larger pots once roots fill the first, in good light (RHS).
-
Or sow direct
Two or three seeds 2.5 cm (1 in) deep per prepared site (RHS; UMD sows 1.3 cm, ½ in), under a cloche or fleece. Thin to the strongest by cutting the others at soil level so you don’t disturb its roots (RHS, UMD).
Planting out
Pumpkins resent root disturbance: handle them gently.
-
Harden off
Get plants used to outdoor conditions first (RHS). Transplants should have three to four true leaves (Utah State).
-
Plant into the prepared pit
Without disturbing the roots; firm gently and water well (RHS).
-
Space generously
Bush varieties 90 cm (3 ft) apart, trailing 1.5 m (5 ft) (RHS).
-
Mark the centre
Push a cane in beside each plant so you can find it for watering once the vines spread (Gardeners’ World).
-
Mulch and protect
Mulch the soil but keep it off the stem (RHS), and cover young plants against slugs. Utah State waits until soil reaches 24 °C (75 °F) before laying organic mulch.
Care
Water deeply, feed hungry plants, help pollination along, and steer the vines.
Water shortage at flowering and fruit set makes flowers and young fruits drop (Penn State).
Care by growth stage
Young plants
Weeds: until leaves cover
Keep weeded and protected from slugs. See planting out.
Vines running
Feed: side-dress now
Guide the stems where you want them. See training.
Flowering
Water: critical now
Male flowers come first. See pollination.
Fruits swelling
Water: deeply
Lift fruit onto a tile and let the sun reach it. See training.
End of season
Frost: harvest first
Water less as fruits ripen, then cut before frost. See harvesting.
Watering pumpkins
Pumpkins need plenty of water, especially when fruiting (RHS). Too little at flowering and fruit set makes flowers and young fruits drop (Penn State).
How much. Deeply and not too often: 2.5 to 5 cm (1 to 2 in) a week (Utah State).
Get it to the roots. Sink a 15 cm (6 in) pot beside each plant and water into it (RHS). Water the base, not the leaves (UMD).
When. Early morning or evening in hot weather, with rainwater where you can (RHS).
Late season. Water less as fruits ripen (Utah State).
Feeding pumpkins
Pumpkins are heavy feeders (UMD), but in well-manured soil most don’t need extra feeding (RHS).
When they do. For big fruits or plants in containers, a high-potassium liquid feed every 10 to 14 days once fruits start to swell (RHS).
Side dressing. US extensions add nitrogen once the vines start running (Utah State) or when fruits first form (UMD).
Not too much. For giant pumpkins, UMD warns that overfeeding makes excessive vines and can split fruits.
Training vines and growing big pumpkins
Limit the spread. Train stems round in a large circle, pinned with short canes, or cut off stems that stray too far (RHS).
Grow up. Small-fruited trailing types can climb a sturdy arch or strong trellis, with netting slings for the fruit. Grow large-fruited varieties flat (RHS).
Lift the fruit. Set developing fruits on a tile, brick or straw to keep them off damp soil, and remove a few shading leaves so they ripen in the sun (RHS, Gardeners’ World).
Bigger fruits. Keep two or three fruits per plant; for a giant, only one, removing any further flowers or fruits (RHS).
Giants. Remove the first two or three female flowers so the plant builds more leaf first. Keep the largest fruit once it is 15 to 20 cm (6 to 8 in) across, then pinch back the vine ends (Illinois, UMD).
Pollination
Pumpkins have separate male and female flowers. The female has a tiny fruit behind the petals (Gardeners’ World).
Males first. Plants produce only male flowers for one to two weeks before females appear. This is normal (UMD, Illinois).
Bees do the work. Poor fruit set is common in rainy weather, when bees are inactive (UMD). Avoid spraying pesticides while plants are flowering (UMD, Illinois).
Hand pollinating. In cold or wet summers, pick a male flower and press it into an open female flower to transfer the pollen (Gardeners’ World).
Pumpkins in containers
Most pumpkins do best in the ground, but very compact bush varieties can grow in a large container or growing bag (RHS).
Container. One plant per growing bag, or per container at least 45 cm (18 in) wide, filled with soil-based compost.
Position. Sunny and open, with room around it for air and the spreading stems. Crowding encourages fungal disease (RHS).
Feed and water more than in the ground: a high-potassium feed every 10 to 14 days once fruits swell.
Problems
Powdery mildew, poor fruit set and slugs are the usual troubles.
Common pumpkin problems
Cold or dry soil and poor pollination cause many pumpkin problems.
Flowers but no fruit
- Normal early
- Poor pollination
The first flowers are male and drop off. Later, poor set means few bees. See pollination.
Seed rots or doesn’t come up
- Cold soil
Sown too early into cold soil. Wait until it reaches 16 °C (60 °F) (Penn State).
Pumpkins won’t store
- Unripe
- Frost
- Damage
Immature, frosted or damaged fruit, or fruit without a stem, doesn’t keep (Illinois). See harvesting.
More problems with pumpkins
Common pests
Slugs and snails
Eat young plants and flowers (RHS). Protect seedlings with a cloche (Gardeners’ World).
Squash bugs
In North America: grey-brown bugs suck sap and leaves wither. Trap adults under boards and hand-pick adults, young and eggs (Utah State).
Cucumber beetles
Striped or spotted beetles chew leaves and can transmit bacterial disease (Utah State).
Aphids
Curl leaves and spread virus. Use a strong jet of water or insecticidal soap (Utah State).
Common diseases
Powdery mildew
White patches on leaves, especially when the soil is dry; it can kill leaves early and spoil ripening (Gardeners’ World, Illinois). Water and mulch well, keep air moving, and pick off infected leaves early on. Some varieties such as ‘Charmant’ have resistance (RHS).
Bacterial wilt
Vines wilt and die, spread by cucumber beetles (Utah State, Penn State).
Mosaic viruses
Mottled, distorted, stunted leaves and misshapen fruit, spread by aphids. Control aphids and destroy badly affected plants (Utah State).
Harvest & Use
Cut ripe, hard-skinned pumpkins with a long stem, cure them, then store somewhere cool.
Harvesting pumpkins
Pumpkins take about 45 to 55 days to mature after flowering (Utah State). Leave them on the plant as long as you can to colour up (RHS).
Ripe signs. Deep, even colour, a rind hard enough to resist a fingernail, and a stem starting to crack (Utah State, Gardeners’ World).
Before frost. Harvest before the first frost, usually late September or October (Illinois). Light frost kills the vines; below about −2 °C (28 °F) the fruit is damaged (UMD). Cover fruit with straw or fleece on a frosty night (RHS).
How. Cut with secateurs or a knife, leaving at least 10 cm (4 in) of stem (RHS); Illinois leaves 7.5 to 10 cm (3 to 4 in). Wear gloves: many varieties have prickly stems (Illinois).
- Full colour, hard rind, cracking stem.
- Before the first hard frost.
- Leave a 7.5 to 10 cm (3 to 4 in) stem.
Curing and storing pumpkins
Only fully ripe, undamaged pumpkins with stems store well (Illinois).
Cure in the sun for a week to 10 days, outdoors or in a greenhouse, to harden the skin (RHS, Gardeners’ World).
Store somewhere dry and airy, with the fruits not touching, at 10 to 15 °C (50 to 60 °F) (RHS). US extensions suggest 10 to 13 °C (50 to 55 °F) (Illinois, UMD). Not in the fridge or anywhere damp (Illinois).
How long. At least three months and up to six, depending on variety (RHS). Check regularly for soft spots.
Eating. Roast, steam or boil the flesh; clean and dry the seeds to roast (Gardeners’ World, UMD).
Propagation
Saving seed, and why cucurbits cross.
Saving pumpkin seed
Pumpkins, squash and gourds of the same species cross-pollinate. It doesn’t change this year’s fruit, but seed saved from it may grow into odd fruit next year (Illinois, Utah State).
Different species don’t cross. Butternut squash, ‘Small Sugar’ and ‘Big Max’ can grow side by side (Illinois).
For true seed of a non-hybrid variety, hand-pollinate and bag the female flower, because bees carry pollen a mile or more (Illinois).
Collect seed from a fully ripe fruit, wash off the pulp and dry thoroughly. Don’t save seed from F1 hybrids.
More to Explore
Quick answers, guides that pair well with pumpkins, and the sources behind this one.
Frequently asked questions
When should I plant pumpkins?
Sow indoors in mid- to late April and plant out after the last frost. See when to plant.
How much space do pumpkins need?
90 cm (3 ft) for bush varieties, 1.5 m (5 ft) for trailing ones.
Why are my pumpkin flowers falling off?
The first flowers are male and drop naturally. See pollination.
Should I hand-pollinate pumpkins?
Only in cold or wet weather, when bees are scarce.
How do I grow a big pumpkin?
Grow a large variety and keep one to three fruits per plant. See training.
How do I know when a pumpkin is ripe?
Deep colour, a rind your fingernail can’t dent, and a stem starting to crack.
Can I grow pumpkins in a pot?
Compact bush varieties, in a container at least 45 cm (18 in) wide. See containers.
How long do pumpkins keep?
Three to six months when cured and stored cool and dry. See storing.
Related guides
Sources
- How to grow pumpkins (opens in a new tab) Royal Horticultural Society
- Pumpkin (opens in a new tab) University of Illinois Extension
- Pumpkins in the garden (opens in a new tab) Utah State University Extension
- Growing pumpkins in a home garden (opens in a new tab) University of Maryland Extension
- Pumpkin production (opens in a new tab) Penn State Extension
- How to grow pumpkins and squash (opens in a new tab) BBC Gardeners’ World