Ah, cucumbers. What would summertime be without their smooth white flesh, moist crunchiness and seductively subtle taste? There simply is no substitute, whether eaten on their own, sprinkled with salt; chopped up into salads dressed with a fruity cider vinegar and peppery olive oil; or stir fried Thai style for an outside-the-box treat.
Though cucumbers are a favoured mainstream vegetable, beneath a façade of propriety lies a secret that is as complex as it is intriguing: a varied sex life worthy of the best racy novels.
But rather than scorn the pansexual life style of cucumbers, we gardeners can embrace it. It is only when we fully understand their behaviour that we can take full advantage of all they have to offer. Fortunately, their sexual proclivities are determined by their flowering habits, and these fall into a few well-defined categories.
Most cucumbers are monoecious, which means they have separate male and female flowers on the same plant. Under normal circumstances, the female flowers need to be pollinated by insects in order to instigate fruit development. Because they have been pollinated the fruit naturally contain seeds, which can get big and tough, adversely affects the eating quality of the cucumber, if harvesting is delayed.
Some monoecious cucumbers are also parthenocarpic, which means that the female flowers will develop into fruit even if they aren’t pollinated. Growers can take advantage of this anomaly to produce highly desirable seedless fruit – all they have to do is prevent pollination, either by removing the male flowers as soon as they appear or, for protected crops, by eliminating insects from the greenhouse or tunnel.
Modern breeding has produced cucumber varieties that produce all, or predominantly all, female flowers – seed catalogues aptly describe these as ‘all female’. Fortunately, they are also parthenocarpic, yielding tender-skinned, seedless fruits of a superb quality. Just occasionally when the plants are stressed they produce some male flowers, and these should be removed to prevent pollination.
Though uncommon, some cultivars such as the oddly-shaped ‘Crystal Lemon’ have male flowers as well as separate hermaphroditic flowers (which have both male and female organs) on the same plant.
© Michael Michaud