Cucurbit
How to grow pumpkins and winter squash
Cucurbita maxima / C. pepo and Cucurbita maxima / C. moschata
Pumpkins and winter squash are tender plants that need the whole frost-free season. Sow indoors from mid April, plant out in early June in full sun on a mound over a hole filled with compost, and water deeply twice a week. The vines run a long way, so give each plant plenty of room in the vegetable garden. Feed potash once fruit has set, limit each plant to a few fruits, then cut before the first frost and cure in the sun so the skins harden for storage.
- Hardiness
- Tender
- Position
- Full sun
- Soil
- Deep, very rich, moisture-retentive
- Ideal pH
- 6.0 to 7.0
- Water
- High, a deep soak twice a week in dry weather
- Feeding
- Heavy feeder
Sowing and planting pumpkins and winter squash
WhenSow Apr to May indoors; plant out Jun; harvest Sep to Oct before frost
This page covers pumpkin and winter squash together. The planting detail below is for pumpkin; where the other differs, it is noted.
Starting off
Sow indoors mid April to early May, one seed on its edge 2 cm deep in a 9 cm pot at 18 to 21 °C, germinating in 5 to 8 days; pot on once, harden off and plant out in early June. Direct sowing under a cloche from late May works on warm soil. Pinch out the tip at 1 m to encourage side shoots.
Spacing and planting
Trailing types 1.5 to 2 m apart each way, bush types 90 cm, each on a mound over a 30 to 45 cm planting hole filled with compost or rotted manure; pin the vines down at the joints to root. Sow or plant 2.5 cm deep. Not a container plant, except mini 'Jack Be Little' in a 45 cm pot.
Varieties worth growing
Pumpkins and winter squash: what is the difference?
Pumpkins and winter squash are grown the same way; the difference is in the kitchen and the store. Most carving pumpkins are Cucurbita pepo, with thin, watery flesh and a storage life of two or three months. Winter squash are mainly C. maxima and C. moschata, with dense, sweet flesh, and the best of them keep for six months. Butternuts, the moschata type, need the longest and warmest season of all and are the least reliable north of the Midlands. Grow a pumpkin for Halloween and for size; grow squash if the aim is to eat well through the winter.
- Jack O'LanternPumpkin
- The standard carving pumpkin: round, orange, 3 to 5 kg, ready in good time for the end of October.
- Atlantic GiantPumpkin
- The one for a biggest-pumpkin contest. Keep a single fruit per plant and give it 3 m of ground.
- Jack Be LittlePumpkin
- Palm-sized fruit, a dozen to a plant, on vines light enough to train up a support or grow in a large pot.
- Crown Prince F1Winter squash
- Steel-blue skin, deep orange flesh and the best keeper of all, six months or more. Needs room to trail.
- Uchiki KuriWinter squash
- The red onion squash. Early and dependable in a cool summer, with fruit of about 1 kg that suit one meal.
- Hunter F1Winter squash
- Butternut bred for British summers, ripening weeks ahead of older butternuts. Sow by mid April.
- Honey Bear F1Winter squash
- Compact, bushy acorn squash with small fruit and good tolerance of powdery mildew: the choice for a small plot.
Month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Check stored fruit weekly and use any that soften. Butternuts will be near the end of their keeping.
- February
Order seed. Crown Prince still eats well from the store.
- March
Dig the planting holes, 30 to 45 cm deep and wide, fill with compost or rotted manure and mound the soil back.
- April
Sow indoors from mid April at 18 to 21 °C, one seed on edge per 9 cm pot. Butternuts first.
- May
Pot on once. Harden off in the last week. Direct sow under a cloche at the end of the month.
- June
Plant out in the first week once frost has passed. Protect from slugs and water in well.
- July
Train or pin down the vines. Hand-pollinate in a cool spell. Start potash once the first fruits set.
- August
Water deeply twice a week. Thin to two or three fruits on large types and lift each onto a tile.
- September
Stop feeding as the skins harden. Remove leaves shading the fruit. Begin cutting at the end of the month.
- October
Cut everything before the first frost, cure for 10 to 14 days and bring into store.
- November
Check the store. Eat pumpkins and acorn squash first.
- December
Check the store again. Keep fruits dry, cool and not touching.
Feeding pumpkins and winter squash
A hungry crop that takes most of its food from the organic matter under it. Build a rich planting station, give one balanced top-dressing, then switch to potash once fruit has set and stop when the skins harden.
A near-bottomless appetite for organic matter, plus a high-potassium feed to size up the fruit.
Feeding plan
March to May, before planting
Garden compost
Two buckets of compost or well-rotted manure in each planting hole, with the soil mounded back over it.
Planting out, early June
Fruit & Vegetable Fertiliser 4-5-6
100 g/m² forked into the square metre around each station, which is 100 g per plant.
Late June, as the vines start to run
Fruit & Vegetable Fertiliser 4-5-6
50 g per plant scattered over the same square metre and watered in. With the planting dose that makes 150 g/m², the label maximum for a season, so no more after this.
From fruit set until the skins harden, every 10 to 14 days
1 to 2 g per litre of water: 10 to 20 g dissolved in a 10 litre can, one can per plant.
Only if older leaves yellow between the veins
1 to 2 g per litre of water, 10 to 20 g in a 10 litre can, every 2 to 3 weeks until new growth is clean.
Signs to watch
Fruit aborting at tennis-ball size
Poor pollination in a cold spell or too many fruit set, not nutrition
Hand-pollinate in the morning and thin to 2 to 3 fruit
Older leaves yellow between the veins
Magnesium locked out by potash feeding
Epsom salts spray
Vast leaves and no female flowers
Excess nitrogen
High-potash feed only
Pests, diseases and problems
Young plants eaten to a stump within days of planting out
Slugs and snails, which favour soft, newly planted cucurbits
Plant out sturdy plants with four or five true leaves, not seedlings; ring each with a cut-down plastic bottle for the first fortnight, patrol with a torch on damp evenings and use nematodes on warm, wet soil.
White powdery coating on the leaves from August
Powdery mildew, brought on by dry roots and humid air late in the season
Keep up the deep watering and mulch the root zone. Remove the worst leaves. Late in the season it does little harm, as the fruit is already made.
Leaves mottled yellow and green, puckered and stunted; fruit small, hard and blotched
Cucumber mosaic virus, carried by aphids and on hands and knives
There is no cure. Pull and bin the plant, wash hands and tools, and control aphids on neighbouring plants. Keep weeds down, since many carry the virus.
Seeds rot in the pot or seedlings stall with yellow seed leaves
Cold, wet compost; the seed needs 18 °C or more and resents overwatering
Sow on edge in barely moist compost, keep at 18 to 21 °C and do not water again until the seedling is up. Resow rather than nurse a checked seedling; a plant sown in early May soon catches up.
Fruit rots where it touches the soil, or in store within a few weeks
Wet ground under the fruit, bruising, a snapped stalk or skins that were never cured
Rest each fruit on a tile or a piece of wood, cut with a long stalk, never carry by it, cure for 10 to 14 days in sun or a greenhouse, and store dry at 10 to 15 °C with the fruits not touching.
Harvest and rotation
Harvest and storage
Cut in late September to October when the skin is hard and the stem has corked, 16 to 20 weeks from sowing. Cut with 8 to 10 cm of stem and never carry by it. Cure for 10 to 14 days in the sun. A plant gives 2 to 4 fruit of 2 to 5 kg. Store at 10 to 15 °C in a dry, airy place for 3 to 6 months.
Rotation and companions
Rotation: cucurbit group with squash, courgettes and cucumber, 3-year gap, usually sited on the compost-heap end of the plot. Sweetcorn and climbing beans in a 'three sisters' block give shelter and nitrogen. Keep away from potatoes, which compete for water, and give it room away from anything it will smother.
Good to knowFor large specimens, restrict to two or three fruits per plant and rest each on a tile to stop it rotting.
Growing in pots
Trailing pumpkins and squash are not pot plants: the vines run 3 m or more and the roots want a barrowload of soil. The exceptions are 'Jack Be Little' and bushy squash such as 'Honey Bear', one plant to a 45 cm pot holding about 40 litres. Fill with multipurpose compost mixed with a third garden compost and the 4-5-6 at 5 g per litre, which is 200 g for 40 litres. Water every day in summer, twice in hot weather, and feed with Sulphate of Potash at 1 to 2 g per litre of water every 10 to 14 days once fruit has set. Expect fewer and smaller fruit than in open ground.
Common questions
When should I plant pumpkins for Halloween?
Sow indoors between mid April and early May and plant out in early June. Carving varieties take 16 to 20 weeks from sowing, so that timing gives ripe fruit at the end of September, with October left for curing. A sowing after mid May is a gamble in most of the UK.
How many pumpkins or squash do you get per plant?
Two to four full-sized pumpkins, or three to six squash of 1 to 2 kg, from a well-fed plant. Small-fruited types such as Jack Be Little give a dozen. For a giant, remove all but one fruit.
How do I know when a winter squash is ripe?
It is ripe when a thumbnail will not dent the skin and the stalk has turned dry and corky. The colour deepens and the fruit sounds hollow when tapped. Cut everything before the first frost, ripe or not, and finish it in the sun or a greenhouse.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.