Muscadines – Pollination
Q: Four years ago I planted a ‘Cowart’ muscadine vine. To this day I have gotten no grapes. Leaves and new growth appear in spring. Little grapes show up, but they never get large and in mid-summer the grapes go away. The plant gets full sun after 11:00 a.m.
A: I am considering seeking licensure as a registered plant sexologist. Public knowledge about the habits of humans and animals seems adequate but I sense a deep need for more information about plants. Each summer I am asked why squash (cucumber, melon, gourd, etc.) flowers fall off the vine without making fruit. The answer is simple: Male flowers appear first. They wither and fall off after being open for only a few hours. Female squash flowers begin appearing several days later. Pretty soon both are opening at the same time and squash amour is the natural result.
Muscadine grapes are a bit different but I believe your problem stems from a lack of sex amongst the vines. You see, some muscadine varieties have perfect flowers, which contain both male and female organs. These varieties do not require another variety nearby to achieve pollination. However, some varieties have flowers with only female organs. These varieties require a perfect-flowered variety nearby to contribute pollen.
My bet is that your grape vine was mis-labeled and you have a female-flowered variety, not a ‘Cowart’. The lack of pollen would explain why the little grapes never develop to maturity.
The cure? Plant a perfect-flowered grape nearby. ‘Cowart’, ‘Triumph’, ‘Nesbitt’ and ‘Carlos’ are all perfect-flowered. If you harvest grapes next year I will use you as a reference in my new profession.