About ten weeks after germination the female flowers will start to appear. They are usually located mid-way down the vine and have a small yellow pumpkin behind their flower. You can hand pollinate by peeling back the petals of the male flowers (these are usually located near the base of the plant), and rubbing the pollen from the male flower onto the stigma in the center of the female flower. Or you can let the bees pollinate for you. Once you have several pumpkins set, change your fertilizer to 20-20-20 ratio and remove all but three of the best pumpkins. When choosing the "right" pumpkins, keep in mind their position on the vine. Their stems should be at a right angle from the vine. The pumpkins should have a round shape and be tall. These tend to grow the fastest. Measure these weekly and take notes. Keep the one that is growing the fastest and discard the others. Prune vines as they grow longer than 10 feet past the pumpkin. As your pumpkin grows, loosen the vine from the soil that is attached to the pumpkin to avoid cracking the vine. When watering, it is best to try to avoid getting leaves wet, as this can raise fungus issues. By the end of July switch your fertilizer to a 15-11-29 ratio, or one high in potassium. The trick to successfully growing a giant pumpkin is to keep your pumpkin growing at an even steady pace, avoiding all stress, keeping it fed and evenly moist.