How to Hand Pollinate Watermelon

Each female flower must receive eight visits from a pollinating insect to set fruit.

Pollination can occur through pollinating insects, animals and wind. Most melons and squash require insects to pollinate the flowers and produce fruit. Melons are a cucurbit just as squash and cucumbers and cross-pollinate with the help of honeybees and bumblebees. Each vine has separate male and female flowers with males developing a week earlier than females. Females produce the fruit and males the pollen. Each female flower is only open for a day and requires multiple visits from insects to become fully pollinated. Hand pollination can ensure fertilization and fruit set at least 50 percent of the time.

Things You'll Need

• Scissors
• Small paintbrush
• Paper towels

Instructions

1. Identify a female flower. They are different from males because there is a swelling at the base where the flower attaches to the stem. This becomes a fruit if pollinated. Attempt manual pollination in the morning. Pollination is most effective between 6 and 9 a.m.

2. Select a male flower and peel back the petals to reveal the stamen or pollen-coated filaments at the center of the flower. Cut the male from the stem leaving enough stem to hold onto.

3. Hold the stem and brush the stamen against the center of a newly opened female flower. Rub the stamens against her stigma, or the stiff pollen receptor, 10 to 15 times. Melon pollen is heavy and sticky and cannot move in wind but requires mechanical assistance.

4. Use the male flower until no pollen remains and pollinate a few other female flowers. You can facilitate the pollen movement by tapping the flower as you rub it on the stigma. You can also collect the pollen on a small paintbrush and paint it onto the female flowers.

5. Cut and store male flowers in the refrigerator for up to three days. Lay the cut end on a moist paper towel on a shelf in the refrigerator. Try not to disrupt the anthers that hold the pollen-coated stamen.

References

• University of Florida IFAS Extension; Home Vegetable Gardening Techniques -- Hand Pollination of Squash and Corn in Small Gardens; Ed Thralls, et al.
• Gardening Know How; Hand Pollinating Melons -- How to Hand Pollinate Melons
• University of Missouri Extension; High Tunnel Melon and Watermelon Production; Lewis W. Jett; February 2006