Pumpkins are easy to start from seed, but you can also purchase seedlings at a local nursery if you are not starting until later in the season. If you do want to grow pumpkins from seeds in a pot, plant them about an inch deep after the soil has warmed up to at least 60 F. There are quite a few things you have to keep in mind in order to reap a pumpkin at the end of the growing season. But, with patience and perseverance, you can grow one (or more than one).
Give Pumpkins Room to Grow
Do not try growing pumpkins in a pot that is less than 10 gallons. If you want to grow more than one plant then 15 to 20 gallons or bigger would be even better. You might also have great success growing pumpkins in straw bale gardens.
Pumpkin vines grow very quickly and some can grow to amazing lengths. Some people train them up trellises or pinch them back. If your pumpkin plant grows on a trellis, you will have to figure out a way to cradle the pumpkins so the weight of it does not break the vine. Some people use stockings or cloth attached to the trellis.
Soil and Drainage
Make sure you use a high quality, fast draining potting soil. The more soil, the better. The soil will retain water and pumpkins need a lot of water.
Good drainage is important for pumpkins. Your pumpkin plant will not grow well if it is sitting in wet soil, so either use a fabric pot like Smart Pots or make sure your pot has lots of holes (or one big hole that won't clog) so the water can drain out.
Sun and Fertilizer
Even small pumpkins need lots of sunshine to develop. Make sure your pot is getting at least six hours of direct sun a day.
Mix a slow-release fertilizer in with the potting soil and then use a diluted liquid fertilizer every couple of weeks during the growing season. You can also sprinkle a dry, slow-release fertilizer onto the top of your soil during the growing season if you choose to not get liquid fertilizer. However, you want to be careful not to give pumpkins too much nitrogen.
You need bees, time, and hand-holding (in some cases) for your pumpkins to grow.
- Pollinators: This sounds obvious, but many places there simply aren't enough bees and pollinators. You can hand pollinate or plant flowers that will attract pollinators near your pumpkins.
- Time: Pumpkins need seventy-five to one hundred days from planting to harvest, depending on the variety.
- Turning: Carefully turn your pumpkins, which usually means flipping them from one side to the other without breaking the stem. You do this for sun exposure and to make sure the pumpkin doesn't flatten on one side. Some people put their pumpkins on a board or on a mesh to keep them from rotting. If your ground is wet for a prolonged period, this is probably a good idea.
Harvest the Pumpkins
When is your pumpkin ready to harvest? The best advice is to wait until the pumpkin skin is hard enough to withstand pressure from a fingernail and until it is a bright orange. Also, when you thump it with your knuckles it should sound a little hollow.
Harvesting pumpkins can sometimes be difficult. The thick stem can be very tough to cut. It's a good idea to use pruning shears to cut your pumpkin off the vine. You want to keep the stem as long as possible, so cut as far from the pumpkin and close to the vine as you can.
After you have cut the pumpkin off the vine, many people suggest to cure it by leaving it in the sun for a week before bringing it inside.