When to Plant Pumpkins in the UK
Pumpkins are a warm-weather crop, and a single cold night can finish off a young plant. That makes timing the most important thing to get right. Start them too soon and you'll have big, hungry plants stuck indoors, waiting for the weather to warm up. Start too late and the fruits may not be ripe before autumn cold sets in.
The ideal window in the UK is fairly narrow, but easy to hit once you know it.
Quick answer
Sow pumpkin seeds indoors in mid to late April, one per small pot, somewhere warm. Plant them outside once the risk of frost has passed, which is usually late May or early June. You can also sow seeds straight into the ground at that time. Pumpkins planted then are ready to harvest in autumn, in time for Halloween. Cut them before the first frost.
Pumpkin planting calendar
Mid to late April: sow seeds indoors in small pots.
May: move seedlings into bigger pots as they grow, and start hardening them off.
Late May to early June: plant out after the last frost, or sow directly outdoors.
June to August: plants spread, flower and set fruit.
September to October: fruits ripen. Harvest before the first frost.
Why pumpkins can't go out early
Pumpkins come from warm climates and can't cope with frost at all. Even a few cold nights just above freezing can slow their growth for weeks. They also dislike cold soil, so seeds sown into chilly ground often rot before they come up.
Hold off planting until night temperatures are reliably above 7°C, which is the RHS threshold for tender plants. Most of southern England usually reaches that point in the second half of May, northern England towards the end of the month, and Scotland in June. Gardens in sheltered towns or by the coast can often plant a little sooner, while cold, exposed sites should wait longer.
For more on frost dates in your area, see when to plant vegetables in the UK
Starting seeds indoors in April
Starting indoors gives pumpkins a head start and protects them from slugs while they're young and easily eaten.
Fill small pots, around 7.5 cm across, with peat-free multi-purpose compost.
Push one seed into each pot, about 1 cm deep, placing it on its edge rather than flat. This helps stop water sitting on the seed.
Keep the pots warm, at around 18–21°C. A heated propagator is ideal, or a sunny windowsill with a clear plastic bag over the pots.
Take off the cover as soon as the seedlings appear, usually within a week or two.
When roots start to show through the bottom of the pot, move the plant into a larger one.
Sowing one seed per pot means you won't need to separate tangled roots later, and pumpkins don't like their roots being disturbed.
Don't be tempted to sow in March. Pumpkin seedlings grow fast, and plants started too early quickly outgrow their pots, long before it's warm enough to plant them out.
Our guide to when to start vegetable seeds indoors covers other crops too
Hardening off
Plants raised indoors need a couple of weeks to adjust to outdoor life before they're planted out. Put them outside for a few hours on mild days, increasing the time gradually, and bring them in at night at first. There's a step-by-step routine in how to harden off seedlings
Planting out in late May or June
Choose the warmest, sunniest and most sheltered spot you have. Pumpkins are hungry plants, so dig a planting hole about 30 cm wide and fill it with a mix of soil and plenty of garden compost or well-rotted manure.
Give them plenty of space:
Bush varieties: about 90 cm apart.
Trailing varieties: about 1.5 m apart, as their stems spread a long way.
Water them in well. If the nights turn cold, cover the young plants with fleece.
Sowing directly outdoors
No room indoors? You can also sow pumpkins where they're to grow, from late May into early June. Warm the soil first by covering it with fleece or a cloche for a couple of weeks. Sow two or three seeds together, 2.5 cm deep, at each planting spot, then keep only the strongest seedling once they come up. Keep them covered until they're growing well.
Direct-sown pumpkins start later than those raised indoors, so this works best for smaller, faster varieties.
Planting pumpkins for Halloween
If you want pumpkins for carving at the end of October, the April and May timings above work well. Most varieties need several months to grow and ripen, so check the days to maturity on the seed packet and count back from late October. Plants that go in late May or early June normally ripen in September and October.
A pumpkin is ripe when the skin has hardened and turned its full colour, and the stalk begins to crack. Cut it with at least 10 cm of stalk attached, and leave it in the sun for a week or so to harden the skin before storing it.
For more, see when to harvest pumpkins
Is it too late to plant pumpkins?
After mid-June, time starts to run out, as pumpkins need a long, warm season to ripen. If you're late, choose a small, quick variety and give it the sunniest spot you have. In September and October it's too late to plant, but it's harvest time, so start planning next year's April sowing instead.
Growing pumpkins in pots
Pumpkins can grow in containers if you give them plenty of room: one plant per grow bag, or one in a pot at least 45 cm wide. The timing is the same as for pumpkins grown in the ground. See growing pumpkins in containers
For the full growing guide, see how to grow pumpkins in the UK
For watering, see how often to water pumpkins
If your plants are struggling, see why pumpkins don't grow
Common questions
When should I plant pumpkin seeds in the UK?
Sow indoors in mid to late April, or sow outdoors in late May or early June once the frosts have finished.
Can I plant pumpkins in May?
Yes. Late May is a good time to plant out indoor-raised plants in southern England, as long as the frost risk has passed. In northern areas, early June is often safer.
When should I plant pumpkins for Halloween?
Sow indoors in late April and plant out in late May or early June. That gives most varieties enough time to ripen by October.
Is it too late to plant pumpkins in July?
It's risky, as the plants may not have time to ripen fruit before autumn. If you try, pick a small, fast-maturing variety and plant it somewhere warm and sunny.
Sowing times, spacing and harvesting advice based on RHS guidance.