The cucurbit family comprises about 954 different species, but we know them as some of the most commonly grown garden crops. Almost every gardener grows at least one of these crops; cucumbers, summer or winter squash, pumpkins, watermelons, and muskmelons. The family also includes gourds but most gourds are poisonous. All cucurbits, except the bottle gourd, have yellow flowers that are either male or female. Flowers that contain both male and female sex organs in the same flower are called “perfect” flowers. Many of these, such as tomatoes and ginseng, are capable of self-pollination but some, such as apples, require pollen from a different tree.
Cucurbits produce separate sexed flowers that are either male or female and they are easy to distinguish. The female flowers have a tiny “fruit” at the base of the blossom whereas the male flowers do not. Inside the male flowers are the stamens that produce the yellow pollen in tiny sacks at the top of the stalks (anthers). If you stick your finger on a male flower, you should see some yellow pollen on it. Cucurbits are bee pollinated and the first flowers that appear are always male. This allows bees to become accustomed to visiting them and by the time the female flowers appear, the bees should be visiting both of them. If you have no bees visiting your flowers, you can manually transfer pollen from the male to the female blossoms using a Q-tip. The female flower has a triangular topped, sticky, stalk in the center of the flower (pistil) that you spread the pollen on with the Q-tip.
When in Bloom — Fry them Up!
A single summer squash plant may fail to produce any fruit at all because of the flower timing issues, whereas four or five summer squash plants may result in you visiting your neighbors at night, in disguise, secretly leaving baskets of zucchini on their door steps. Other times, too much nitrogen fertilizer will result in huge plants that do not flower at all. The good news is that the flowers may be dipped in batter or stuffed with cheese and fried! They are delicious!
Pumpkins are notorious for failing to “set” any fruit until late summer regardless of when you set them out. Pumpkin blossoms are only open for about six hours beginning at sunrise, which does not give bees a lot of time to do their job. Hot, or cold, or humid weather will delay the production of female flowers, as will too much nitrogen in the soil or drought or soggy soil. Winter squash, such as butternut, acorn, or “turban” types are generally not so fussy.
Stomping Out the Pests
All cucurbits have more than their share of pest problems. Grey colored, shield shaped, squash bugs often wipe out plantings in a few weeks, especially if the squash is grown in the same area for more than a season. These hard-shelled bugs are pretty much invulnerable to most insect sprays once they get a foothold. You can look for their geometric shaped blocks of gold colored, egg masses on the underside of the leaves and squish them with your fingers, or just remove the entire leaf from the garden and stomp on it.
Cucumber beetles are harmless looking, little (one-quarter inch) beetles that have either black stripes or black spots on a yellow back. They look a bit like tiny fireflies. The larvae eat the roots of all cucurbits and also about 30 other garden crops. The real threat is that they also transmit several fatal diseases, including Mosaic virus, which causes leaves to turn yellow and often mottled yellow and green.
All these insect pests are easier to prevent, before you see a serious problem, then to control once they show up.