Before you begin growing giant pumpkins its wise to think about how much space you have to spare!
Having obtained your seeds, start them off as soon as possible in a small pot in a warm, bright place, like a sunny windowsill. Sow individually just under the surface into 3" pots of multi-purpose compost and germinate indoors at 20 to 24 degrees. A handy tip is to plant the seed sideways into the compost to avoid water sitting on it and causing rot. In a week or so, two weeks at most, the seed should have germinated.
Once the plants starts to grow, keep them warm in a greenhouse or coldframe. Growth will be quite fast, so transfer into larger pots if the roots start coming through the bottom of the pot.
Start hardening off by opening the frame or greenhouse in the day and once the risk of frost has passed, plant out, preferably under a cloche until the plant gets too large.
Pumpkin plants grow very big, so your pumpkin patch should measure at least 4.6m by 6.1m (15ft by 20ft). For planting, dig a hole about 2 feet square and deep, fill with good compost or mix well rotted manure into the soil. The soil should end up slightly mounded.
You need to take your soil improvement techniques to a higher level to grow a really huge pumpkin. Many growers use well-rotted horse manure. Pumpkins, like courgettes and melons, need warmth around their leaves and roots. Horse manure has an open structure which means it warms the soil faster than richer cow or pig manure. Broadcaster and author, Toby Buckland, in an article in Kitchen Garden magazine (Feb.2012) says that he is using enhanced green compost in an attempt to grow a record-breaking pumpkin this year. This is made from the contents of the council-collected green or brown bins and contains food waste as well as the usual garden clippings. This gives it the higher nutrient content that pumpkins love. The compost gets very hot so all pathogens are killed and when its blended with soil for your pumpkin bed, it should encourage fast rooting and help keep frosts at bay.
Pumpkins need lots of water, so be sure to water them daily - dont let them dry out!
Once you have 3 fruits starting to form, remove any further flowers that develop. You need to concentrate everything into just one pumpkin. Once the three small pumpkins have started to grow, choose the best one and pinch off the others.
Toby Buckland suggests "When the fruit reaches football size, its time to place it on its side on a bed of straw with the umbilical stem kinked into a U where it meets the stalk. This ensures the stem doesnt stretch to breaking point as the gourd grows, while the straw acts as a soft bed, keeping the skin safe from stones in the soil". It can also be an idea at this stage to put the pumpkin on a palette, if you can lay your hands on one. This will help with moving your pumpkin when its grown into a whopper!
Some slug defence is always a good idea as well!
Click here for more information on growing pumpkins in our article 'How to grow pumpkins for Halloween'.
More useful information can also be found at the following website www.allotment.org.uk.