Karen has a question about why her Seminole pumpkin is dropping all its fruit:
“I had beautiful vines (the leaves were mottled — gorgeous even without fruit (…) but the hurricane wiped them out.
Although the vines (…) flowered well, the blossoms all fell off or produced only little pumpkins which then shriveled up and died. 🙁 … so I wanted your advice on what the problem most likely was. Lack of calcium or some other mineral? The soil had been enriched over the course of several prior years, with virtually nothing else growing except some weeds that I took care of organically.”
My bet is a pollination issue.
Pumpkin vines make two types of blossoms: male and female. Pollen from a male bloom must travel to a female bloom in order to make a pumpkin.
This requires some sort of pollinating creature – usually bees. The female bloom has an ovary at its base which will develop into a pumpkin if pollinated. The ovary looks just like a little pumpkin. If it does not receive pollen, it drops off.
It sounds like Karen’s vines were otherwise happy and healthy, at least until the hurricane came, so chances are there was a lack of bees at the proper time. Sometimes this is because the bee population is low; other times it can be because of inclement weather during blooming.
Pollinating Seminole Pumpkins
Fortunately, hand-pollinating is easy. Just take a paintbrush or a Q-tip or even the tip of your finger, then brush some pollen from the male blooms and take it over to the female blooms and but the grains on the stigma. Most times the “little pumpkin” at the base of the bloom will grow instead of falling off.
If there is no pollen, there are no seeds to develop, and if there no seeds, there is no reason for a vine to put effort into developing a fruit.