You must get the right type of pumpkin seeds to get a giant pumpkin. Some large pumpkin seed varieties include Prizewinner Hybrid, Atlantic Giant, Mammoth Gold, and Big Max. Many of these seeds are available online for around $1 each.
Giant pumpkins need lots of time to grow. Start growing your pumpkins inside in a pot before transplanting outside. May is a good month to start the giant pumpkin seeds.
Once you are sure that the danger of frost has passed in your region, transplant your little pumpkin plants outside. Make sure to put them in a good quality soil with a PH around 6.5. Fertilize often per the directions on your specific fertilizer. Consider using organic fertilizer to be more eco-friendly.
Keep the pumpkin plants protected from wind. You can build a fence or use plastic to create a wind break. Also be on the lookout for bugs that may be damaging your pumpkins. Remove the bugs and any infected pumpkins from your garden so the entire crop is not affected.
As soon as you see pollen on the pumpkin flowers, get a jump start on mother nature by hand pollinating the pumpkin flowers. You can do this by getting a small paint brush and brushing the pollen from one flower to all the other flowers. You must have the male pumpkin flower pollen mingle with the female pumpkin flower pollen to create a pumpkin.
For a pumpkin to grow really big, it needs as many nutrients from the vine as possible. In order to get the most nutrients, there should be only one pumpkin per vine. Notice which pumpkins are attached to which vine. Select the best and biggest pumpkin per vine and remove all the other pumpkins.
Continue to water and fertilize your pumpkins until it is time to harvest.