Pumpkins are easy to grow from seed and can be sown outdoors in the spot where they are to grow, or you can start them off indoors in pots.
Sow two or three seeds 2.5cm (1in) deep outdoors in late May or early June and cover with cloches, jars or plastic; leave in place for two weeks, or as long as possible, after germination. Thin the seedlings to leave the strongest one.
For earlier crops or in cold regions sow seeds indoors on their side 13mm (0.5in) deep in 7.5cm (3in) pots of compost from mid- to late April at 18-21C (65-70F).
If you don’t have the space to raise pumpkin seedlings, you can also buy young plants from garden centres in spring and these usually can be planted outdoors straight away (check with the shop when you buy them).
Two weeks before planting or sowing seed outdoors, make planting pockets 1.8m (6ft) apart. Do this by making a hole about a spade’s depth, width and height and fill with a mixture of compost or well-rotted manure and soil. Sprinkle a general fertiliser over the soil. Plant one plant or seed on top of each pocket.
For indoor-raised seedlings, plant outside on top of your planting pocket in early June, hardening off (acclimatising) before doing so. Do this by moving them into a coldframe for a week or, if you don’t have a coldframe, move plants outdoors during the day, then bring in at night for a week. The following week, leave them out in a sheltered spot all day and night.
You can also grow pumpkins in growbags or containers (at least 45cm/18in wide). Plant one or two per growbag, or one per container.
Keep the soil constantly moist by watering around the plants not over them. As they need plenty of water, sink a 15cm (6in) pot alongside the plants when planting out. Water into this and it will help ensure the water goes right down to the roots and does not sit around the neck of the plant, which can lead to rotting.
Feed every 10-14 days with a high potash liquid fertiliser once the first fruits start to swell.
The fruit of pumpkins should be supported off the soil on a piece of tile or glass.
Let the fruit mature on the plant and remove before the first frost strikes.
‘Becky’: A classic orange medium-sized Hallowe’en pumpkin perfect for carving. Prolific and high yielding.
‘Rouge Vif d’Etamps’: A really stunning pumpkin with red, ribbed skin and moist orange flesh. Growth is vigorous and trailing.
Powdery mildew: This is a common fungal disease for squashes, especially in dry conditions when plants are under stress. You will see white, powdery patches of fungus on leaves, stems and in severe case, the fruits.
Remedy: Mulching and watering reduces water stress and helps make plants less prone to infection. Promptly removing any infected shoots will reduce subsequent infection. There are no chemicals to treat powdery mildew, but you can use plant and fish oils as a preventative.
Read more information on powdery mildew
No fruit, or fruit rotting when very small: This is a physiological problem, caused by the growing conditions, not a pest or disease. It is a problem when the weather in early summer is cool and this causes inadequate pollination.
Remedy: This is usually a temporary problem and once the weather starts to improve, so will pollination. You can try to hand-pollinate plants yourself by removing a male flower (they don’t have a swelling at their base) and brushing the central parts against the centre of a female flower (female flowers have a swelling at the base – this is the beginning of the fruit). But this is a bit of a hassle, and normally the plant will correct this problem itself.
Grey mould: This is a problem normally in wet conditions and is usually worse on weak or damaged plants. The mould usually enters through a wound, but under the right conditions even healthy plants will be infected. You will see fuzzy grey mould on affected buds, leaves, flowers or fruit. Infected plant parts eventually shrivel and die.
Remedy: Hygiene is very important in preventing the spread of grey mould. If you see grey mould, remove the infected material and destroy. Grey mould is encouraged by overcrowding, so make sure you plant your pumpkins at the appropriate distance apart. No fungicides are approved for use by amateur gardeners against grey mould. Products containing plant and fish oil blends may be used but are unlikely to have much impact.
Readmore information on grey mould