for cooking i grow the variety 'Sugar Baby'. for showing off i grow 'Cinderella' aka 'French Market', and around here lots of the farmers grow 'Dills Atlantic Giant' which is big enough for Peter Punkin'eaters wife, kids, dogs and in-laws to live in. they carve them with chainsaws... truly a huge, misshapen goliath of a vegetable and just about totally inedible. even cows wait until the first freeze turns them into mush before they'll touch them.
pumpkins are heavy feeders, so i grow them in composted kitchen waste mixed with dirt. they also like their water, but to avoid a killing case of powdery mildew water them around the roots under the leaves, not ON the leaves.
its the nature of punkies to get kind of buggy and moth-eaten towards the end of the season, and since they're an annual i don't much pay attention. if the end of a particular vine molds i'll cut the damage away; same with leaves. otherwise i just let them be.
some folks get carried away and make special raised beds for them out of drip-irrigated bark mulch and have box fans running on 'low' day and night to keep the mold away...AND water them with skim milk. all this love is supposed to produce a superior fruit...
Grpwing pumpkins 
