Dills Atlantic Giant
Giant Pumpkin (Squash) in the US

You'll want to sow your giant pumpkin seeds either indoors a few weeks before your last frost date, or directly into the soil once it's properly warmed up. For zones 8 and 9, March or April is usually a good start. In zones 6 and 7, aim for April or May, and for zone 5 folks, May is your best bet. Plant them about an inch deep. If you're sowing indoors, a little pot on the windowsill is fine, then move them to a cold frame if it's still chilly outside before planting out. Make sure the soil is warm enough for direct sowing, that's key.

These plants need loads of space, like I say. Once your indoor seedlings have a few true leaves, harden them off for a week or two before planting them outside after all danger of frost has passed. Give each plant a good 10 to 20 feet (3 to 6 meters) in every direction, honest. They're proper spreaders. You won't be growing these in a pot on the patio, not if you want a giant, anyway!