What kind of fertilizer does he use? Could be too much nitrogen, but some pictures would be really helpful. Also I see you are in zone 4 it is entirely possible your growing season is too short and you can never get pumpkins. Pumpkins take around 90 - 110 days depending on variety before you'll have ripe pumpkins. Are any of your neighbors able to grow pumpkins? When do you plant and when does frost kill your plants?

We put a lot of oak leaves in the garden as mulch in the fall,and just a regular (I think it's Tone) fertilizer. People grow pumpkins like crazy up here, but not us. We plant in late May or early June so that isn't it either. We get great gourds, cukes and tomatoes. What a mystery.

How big is your patch and how closely do you plant your pumpkins? Glad you're getting gourds they're fun to grow at least! Also What varieties have you tried? Are you going for a jack-o-lantern type pumpkin (or bigger) or are you trying for smaller pie pumpkins?