I planted three mounds of different pumpkins and none of them produced any fruit even though all the vines looked healthy. I tried to pollinate the flowers myself but noticed that all the flowers were male - no females. How is that possible? Can any environmental conditions cause this or is it simply bad seed (purchased form a hardware store)? I live in the Dayton, OH area.
Certified GKH Gardening Expert
Bad or old seed is a possible but it also may be to much Nitrogen in the soil.
This could cause lack of flowers.
Also it is common for the plant to produce male blossoms first and then the female blossoms come later.
Here are some links for you with more information.