At first glance, it may appear that all of the flowers on your pumpkin plant are the same. A closer inspection reveals distinct differences between the female flowers and the male flowers. Pumpkin plants — and other “cucurbits,” such as melons, cucumbers and squash — have both female and male flowers. Being able to detect the differences will be especially important if you plan to pollinate the flowers by hand.
Look for the flowers with the long and thin stalks. These are the males. They’ll typically appear before the female flowers, and they’ll also be more abundant.
Look for the stamens. Another distinguishing feature of the male flower is the presence of what appears to be a single stamen — the rod-shaped, pollen-producing part of the flower that protrudes from the center. On a male pumpkin flower, however, what appears to be only one stamen is actually more than one stamen fused together.
Look for the flowers with the short and thick stalks. These are the females. Underneath the female flower, you’ll also notice a green, berry-sized ovary — the part that swells into a pumpkin after fertilization takes place. Fertilization is also followed by the shriveling up of the female flower.
Look for the stigma. Female flowers can be identified by the multi-segmented stigma in the center. The stigma is the pollen-receiving part of the flower.