Cross-Pollination of Melons

Flower Types

• All melon vines produce different gendered flowers. The first blossoms displayed on the vine are male, but after that the plants produce both male and female blossoms. A notable exception is cantaloupe and muskmelon. These plants produce male flowers and bisexual flowers. Only female flowers yield fruits, which are enlarged ovaries. Male and female flowers both look like papery, yellow trumpets on melon vines. Distinguish them by the smooth, narrow flower stem neck and pollen-shedding stamens in male blossoms, and the bulbous flower stem neck and rounded pistil in female blooms.

Pollination

• Melon blossoms open in the morning and close by dusk, lasting only one day. When open, honeybees visit the flowers and transfer pollen among them. Multiple visits are needed to ensure full pollination of female blossoms. Fruits form only after the pollen grains burrow into the female pistil to reach the ovary and fertilize the eggs within. This fertilization results in seed production in the sweet, juicy compartment inside the mature melon.

Cross-Pollination

• Although melons are in the same plant family, most are different species. Only pollen from plants of the same species can result in pollination and fruit production. Watermelon (Citrullus lanatus) flowers cannot supply pollen for cantaloupes (Cucurma melo), or vice versa. However, cantaloupes, muskmelons, casaba and honeydew are all forms of the same species. Therefore, these closely related melons can cross-pollinate each other's flowers. Cross-pollination does not affect quality of the fruit flesh or other attributes. The only result is hybrid genes in the seeds -- which is not known until those seeds are germinated and evaluated.

Myths

• Regional garden folklore often blames poor-tasting or misshaped melons on cross-pollination between various vining vegetable and melon crops. This is untrue as only pollen from plants that are the same species results in development of fruits. The cause of poor quality melons is infertile soil, excessive rainfall, or a lack of insect pollinators when flowers are open. Cool, rainy weather can inhibit plant development -- flower production or fruit maturation -- as well as not be conducive for honeybees to venture out from the hive to pollinate flowers.