
Cucurbita pepo
Pumpkins are vigorous annual vines grown for their large, colourful autumn fruits. They thrive in warm, sunny conditions and produce long, sprawling stems that can easily run several metres. Pumpkins are frost-tender and need a good, rich soil and consistent watering through summer. With enough warmth and space, they reward you with hard-skinned fruits that store well and are ideal for both cooking and seasonal decoration.
Step-by-step instructions for growing Pumpkin
Change the guide to see different planting timelines and tips.
Step by step on growing pumpkins outdoors (start indoors, transplant outside).
Fill small pots or seed trays with peat-free seed compost and sow one seed per pot about deep. Lay each seed on its side to help prevent rotting. Water gently and cover the pots with a propagator lid or clear bag to keep warmth and moisture in. Keep the pots in a bright place at around . Seeds usually germinate quickly in these warm conditions. This period, around February in Abergwynfi, is ideal for giving your plants an early start before outdoor weather improves.
Once seedlings have developed their first true leaves and the roots are beginning to fill their pots, move each plant into a larger pot. Use fresh peat-free compost and handle the seedlings gently by the leaves rather than the stems. Keep them in a bright, frost-free place and water regularly to maintain steady growth. Potting on gives them more room to establish before they face outdoor conditions.
March in Abergwynfi is the right time to begin hardening off your young pumpkin plants. Place the pots outdoors in a sheltered spot during the day and bring them in again at night for about a week. Gradually increase their time outside each day. This gentle acclimatisation helps toughen them up and prevents shock when they are finally planted into the garden.
Once all risk of frost has passed and the soil has warmed nicely, transplant your pumpkins into their final positions. Choose a warm, sunny and sheltered place with rich soil. Dig a generous planting hole, mix in plenty of compost, and set the plant at the same depth it was growing in its pot. Space plants about apart to give each one lots of room to trail. Water thoroughly after planting, and consider using fleece or cloches at night if the weather still feels cool.
Pumpkins are hungry plants and appreciate regular feeding. About two weeks after transplanting, begin feeding with a liquid fertiliser every couple of weeks. Keep the soil consistently moist, especially in warm spells. Once fruits start forming, switch to a high-potassium feed such as tomato fertiliser to support healthy swelling. Water well before and after feeding to help nutrients move through the soil.
As the vines begin to run, guide them so they don’t tangle or overrun nearby plants. Once a few fruits have begun to set, you can pinch out the growing tips to encourage the plant to put its energy into swelling the pumpkins rather than extending more vines. Remove any very late-developing fruits so the plant concentrates on ripening the strongest ones. These simple tasks help produce larger, better-shaped pumpkins.
Pumpkins are ready to harvest once they have turned a deep, rich colour and the skins have hardened so you cannot dent them with a fingernail. This usually falls between October and November in Abergwynfi. Cut them from the vine with a sharp knife, leaving a decent length of stalk attached to help them store well. Handle fruits gently and cure them in a warm, dry spot for a week or two to toughen the skins before storing somewhere cool and frost-free.