Pumpkin Vines Flower Repeatedly but Do Not Produce Pumpkins

[Butch]

I planted pumpkins in March from the seeds of the pumpkins we bought back in October for Halloween. I had thrown the seeds in my compost bin. When I moved the compost bin in March to expand my garden, the pumpkins started sprouting.

The pumpkins have been producing flowers, but they never seem to turn to fruit like the flowers on my squash plants do. Someone told me my pumpkins might not produce because they are hybrids. I don't know what type of pumkins they are--I bought them at the grocery store.

Should I have seen pumpkins start on my vines by now? If not, I'm considering removing them from my garden.

[Binkalette]

Have you seen any female flowers yet? Usually they produce all male flowers first. The females will have a tiny pumpkin behind them, like many squash plants do. If you see females, but they aren't setting, try hand pollinating them, the bees might not be doing it.

[applestar]

How long has it been flowering?

I keep saying this because this has been my experience with cukes, pumpkins, melons, and watermelons (not as much with summer squash...) -- typically, I've observed male flowers start to bloom and new ones will continue to open for about a week with no sign of female blossoms. When about 12~15 male blossoms have opened, I notice immature female blossoms begin to form on the vines.

My working theory is that the male blossoms open first to attract local pollinators so that by the time female flowers begin to blossom, there will be regular and large population of pollinators to effectively pollinate them.

[orgoveg]

I did the same thing just for grins. I have one plant left that is the only one not affected by the vine borers. It was the one sown with seed from a grocery store jack-o-lantern. It has lots of male flowers and I've only found two female flowers forming near the end of the vine. When they open, I intend to hand-pollinate them although there have been enough honey bees around lately. The females are the ones with the bulbs behind the blooms. Unless you see no female flowers at all, I think you just have to wait and see.