The edible cucurbits that we grow in our edible garden, namely, pumpkins, luffas, cucumbers, rockmelons, watermelons and various squashes, have unisexual flowers where the male and female flowers occur separately on the same plant and the term “monoecious” is used to describe this phenomenon.
The sexes of cucurbit flowers are quite easy to tell apart. Female flowers have an obvious baby fruit behind the petals whereas you don’t find any behind the petals of the male flower. This is the description that I have often used to tell visitors as well as my gardeners in the community garden.
In the lowland tropics, pollination of cucurbit flowers that open during daytime should not be a problem since insects such as bees will automatically visit the flowers and help transfer the pollen.
If you face problems with fruit set, your plants may need your help to assist in the pollination of the flowers they produce. Here’s a step-by-step guide as to how you can play the role of the matchmaker… In this example, I am using the flowers of the cucumber.
The male flower of the cucumber – there isn’t a baby fruit behind the petals.
Once you have identified a male flower, pluck it off the vine and strip off all its petals.
Here’s a picture of a female cucumber flower. Notice there is a baby fruit behind the petals. To pollinate the female flower, lightly brush the pollen laden anthers of the male flower with the pistil of the female flower. In doing so, you transfer the pollen from the male flower to the female flower.
Once pollination is successful, the female flower will wilter and develop into the cucumber fruit.