We Live In Southeastern Kentucky In Knox County. We Have…
We live in southeastern Kentucky in Knox County. We have grapevines that start out fine but when the grapes start to get ripe they rot. Do we need to fertilize our vines?
The Gardener’s Answer
Hello, Vivian: I do not think fertilizing is the issue with your grapevines. Although making sure they have enough nutrients is important to your grapes, this sounds more like a fungal problem. The most common problem found with grapes grown in Kentucky is known as black rot. This is a fungus that will cause infected berries to shrivel up and look more like raisins than grapes. It can be controlled by good sanitation and potentially a spraying program, but the most important step in eliminating the problem is to have it positively identified. I cannot do without seeing your vine so you should take a sample to your County Cooperative Extension Service for the agriculture/horticulture agent(s) to look at. The Extension Service also has publications available to home gardeners; the following link is one on growing grapes in Kentucky: www.ca.uky.edu/agc/pubs/id/id126/id126.htm
. Black rot will overwinter so good sanitation practices are very important in keeping insects and disease problems under control. Remove and dispose of all infected grapes still on the vine as well as the ones that have fallen. Keep the area around your vines free of all plant debris. As with all plant material, if we do not give them ideal conditions to grow in we are making them more susceptible to insect and disease problems. Grape Vines should be planted in full sun with good air circulation.