Pinching Watermelon/Canteloupe Vines

Asked August 14, 2013, 1:02 PM EDT

As we were very wet until July st we didn't get into the garden to plant until July 4th-5th. The watermelon are just starting to vine ; would it hurt to pinch the ends of the plants/OR leave less flowers to grow into melons,( before long), to produce less fruit but more regular size ones?
I should add that the Watermelon we plant is "Bush Sugar Baby" which the maturity date is 65 days.
The Cantaloupe we planted is either Ambrosia (approx. 88 days) and "Moneyloupe (which is 72 days).

Thank You very much for your input and for trying to answer my question!

Howard County Iowa

1 Response

Thanks for contacting eXtension! There are two things to remember here.

You planted your crop very late and poor pollination could defintely be a factor. Cucurbits (watermelon, cantaloupe, pumpkin, cucumber) are different from other vegetables in that they have separate male and female flowers on the same plant. Only the female flowers will produce fruit. The first flush of flowers on a cucurbit are male. They may remain on the plant for a day then fall. Female flowers, which are usually a week or two behind are the fruit producing flowers. There will always be many more male flowers than there will be female. Female flowers can be distinguished by the small fruit at the base of the flower. The flowers are usually only open and fertile in the morning hours. Insects are necessary for the transfer of pollen, if they are not well pollinated the fruit will be misshapen or stay small and shrivel up (falling from the plant). Be careful spraying broad spectrum pesticides around cucurbits because pollinating insects (bees) are harmed also. If you are having a pollination problem, you can hand pollinate. Take a open male flower and hold it over the female flower and shake it to drop the pollen. You can also take a Q-tip, rub it in the male flower to gather pollen, then transfer it to the female. Don't try to remove flowers unless you can tell the difference!

As for the size of the plant, you can trim back watermelon vines to somewhat control the size and cause more stem shoots but the watermelon will get to be a very large plant regardless of how much you tip the runners. Watermelons are planted in early spring. Trying to mature melons in the heat of summer causes poor fruit set and development. If you are not getting both types of flowers, you may have planted too late or be growing in too much shade -- melons MUST have 8-10 hours of direct sun daily. Hope you have a successful crop.