the pumpkins are white, soft and 'rotting' on the vine. What might cause this? The biggest pumpkin is doing fine, and one of the newest pumpkins are okay so far. Thanks!
Have a look at this webpage: Cucurbit Fruit Rot Issues – Why Pumpkins And Squash Rot On Vines and decide which disease best fits your particular situation. From the short info you supply and without a picture it would be difficult for us to help you more.