|For the last three years, our grapes start off fine, but get black rot and shrivel up later in the summer. Last year, we sprayed them once a week, but they still died. We are about ready to dig them out and start all over. Any suggestions?|
|I certainly understand your frustration, and unfortunately starting over may not solve the problem. Grapes are subject to such a wide range of problems that most home gardeners find they must rely on a regular spray program to produce a good crop every year. Some varieties are more prone to problems than others, and some of the problems actually begin very early in the year but do not become apparent until late summer so it is important to accurately identify the problem and then to follow an appropriate spray regime to combat it. (In many cases the timing is critical.) Your local County Extension (765-7878) should be able to help you determine the best routine for your particular plants based on the prevalence of specific problems and weather patterns in your local area. They may also be able to suggest varieties best suited to your local conditions.
In addition, many of the problems are carried over from year to year on plant debris, so be sure to follow proper pruning practices and remove and destroy all traces of the trimmings. Removing any affected leaves or fruit during the growing season is also a very good step towards reducing reinfection. Finally, grapes do best in full sun in a spot with good air circulation. Good luck with your grapes!