If you want to get serious and get the biggest pumpkin you can you can actually feed the milk to the pumpkin. Pick off all the pumpkins on the vine except the biggest pumpkin. Then take a bowl with milk and sugar in it and place it by the pumpkin. Very carefully take a knife and make a small slit in the stem near where the pumpkin is starting to grow. Put a piece of cotton wick into the slit and put the other end of the wick into the milk and sugar. Make sure the wick is soaked with the milk and sugar first. The pumpkin will suck up the milk and sugar mixture and grow bigger. Keep the bowl full of the milk mix all the time and watch the pumpkin grow.