Growing Pumpkins for Halloween

A home-grown jack-o'-lantern beats a supermarket one every time, and pumpkins are one of the most rewarding crops to grow with kids. The trick in the UK is timing: pumpkins need a long, warm season, so you sow in late spring to have big, ripe fruit ready for late October. Get the sowing right and the rest is mostly watering, feeding and waiting.

Pumpkins are a type of winter squash, so everything in the main squash growing guide applies here. This is the Halloween-specific version: how to land a carving-sized fruit on the right date.

Sow in time for October

Pumpkins are frost-tender and slow to swell, so they need every warm week the UK summer gives. Sow seeds indoors from late April to mid-May in 7–9cm pots — on their side, about 2cm deep, somewhere warm and bright. They germinate fast.

Harden the plants off and plant them out only after the last frost has passed, usually late May to early June depending on where you are. Check your own date with the frost date checker, and use the planting calendar to map it onto your year.

Don't be tempted to sow much earlier indoors — the plants sulk and outgrow their pots before it's warm enough to plant out. Mid-May sowings often catch up.

Best carving varieties

For Halloween you want size and a smooth, even shape — not flavour. The classic carvers are:

• 'Jack O'Lantern' — the reliable, medium-large, round orange pumpkin that's bred for exactly this. The best all-round choice.
• 'Mammoth' (and similar giant types) — for a showpiece. They need lots of space, water and feed, and one fruit per plant.
• 'Harvest Moon' F1 — a tidy, bright-orange, hollow-ish carver that ripens well in our shorter season.

If you'd rather eat your pumpkin than carve it, pick a flavour variety like 'Crown Prince' from the squash guide instead — carving types are watery and bland on the plate.

Growing big fruit

A good Halloween pumpkin comes down to a few simple moves.

One fruit per plant. A plant will set several small pumpkins, but to get one big carver, let two or three fruit start to swell, then pick the best one and remove the rest. All the plant's energy then goes into your chosen pumpkin.

Feed and water hard. Pumpkins are greedy and thirsty. Water deeply at the base in dry spells, and once the fruit starts swelling, feed weekly with a high-potash tomato feed — the same feed you'd use on tomatoes or courgettes. A mulch around the base holds moisture and keeps weeds down. They'll happily grow on a compost heap, which is rich and moisture-retentive.

Slip a board under the fruit. Once a pumpkin is sitting on soil it can rot from below in our damp autumns. Slide a tile, a piece of wood or a slate under it to lift it off the wet ground and let air circulate. Turn it gently now and then for an even colour.

Ripening and curing before Halloween

A pumpkin is ready when the skin turns deep, even orange, sounds hollow when tapped, and the stem starts to crack and dry. In a UK garden that's usually late September into October — nicely timed.

To help the last fruit colour up, snip away leaves shading it so it catches the autumn sun, and ease back on watering in the final couple of weeks. Cut it before the first hard frost, leaving a good 10cm handle of stem attached (never carry a pumpkin by its stem).

Then cure it: leave it somewhere warm, dry and airy — a sunny windowsill, porch or greenhouse — for about 10 days. Curing hardens the skin so your jack-o'-lantern lasts longer and doesn't go soft mid-week. A cured carving pumpkin keeps happily until the 31st; once carved, it'll last only a few days, so cut it the day before.

For everything on growing, spacing and the eating varieties, head back to the full squash guide.