Pumpkin flowers are large orange or yellow-colored blooms that grow on long vines and produce pumpkins! On the standard ready-for-fall growing schedule, these flowers begin to bloom mid-June to early July. Healthy vines produce flowers from this time until the first frost.
For successful pollination to produce pumpkins, female pumpkin flowers need to be pollinated by male flowers.The male flowers outnumber the male flowers 10:1 and typically start showing up about two weeks before a female shows up.
Growers may think their female flowers never opened, which can happen, but it is more likely the grower just missed it. Most female pumpkin flowers open for just one morning and close up by afternoon of the very same day. Each female can produce one pumpkin. It is easy to identify the soon-to-be pumpkins on female flowers right below the petals.