green grapes drying up - Ask Extension
my grapes get nice big and green then get burgendy colored and then just dry up to a small pea size?i have never grown grapes before, i baught a house...
Knowledgebase
green grapes drying up #267470
Asked August 04, 2015, 1:11 PM EDT
my grapes get nice big and green then get burgendy colored and then just dry up to a small pea size?
i have never grown grapes before, i baught a house that had these grape vines. should i water them by hand more? and what should i do before winter for them?
thank you (please also email me back.)
tom
i have never grown grapes before, i baught a house that had these grape vines. should i water them by hand more? and what should i do before winter for them?
thank you (please also email me back.)
tom
Winneshiek County Iowa
Expert Response
How exciting to "inherit" fully grown grapes along with your new house. They are generally pretty easy to care for, though will require some pruning to keep them under control.
It is impossible to diagnose a problem like this definitively from just a photograph, but the images suggest grape black rot. An earlier eXtension question also dealt with this so here is the link to that response: https://ask.extension.org/questions/199835#.VcEmRvkiST_
Conditions like this have many complicating elements for a definitive diagnosis, more than just what they look like in the instant of the photograph. So to help you perhaps narrow things down since you know how the vines have been all season and can look for more specific features, here is a very detailed list of grape diseases with excellent information about how they happen and what can be done: http://www.agr.gc.ca/resources/prod/doc/sci/pub/pdf/id_guide_major_diseases_grapes_e.pdf
In case it is black rot, here is some additional detailed information on that infection specifically: http://ohioline.osu.edu/hyg-fact/3000/pdf/HYG_3004_08.pdf
The good news is that there may be fairly simple ways to help reduce the incidence in future seasons. There are many readily available websites and print sources that discuss the many details of pruning and caring for grapes: they've been around for centuries and folks have invented many systems for them. But the basic line is that they benefit from very hard pruning in late winter. Although it seems hardly anything is left, they rebound with such exuberance once they get growing. I find that during the summer I also do some nipping and pruning to keep them a bit under control. So, have a look online and pick a pruning system that works with their location (on an arbor versus an espalier for example), and just be brave next winter in cutting them back!
Good luck!
It is impossible to diagnose a problem like this definitively from just a photograph, but the images suggest grape black rot. An earlier eXtension question also dealt with this so here is the link to that response: https://ask.extension.org/questions/199835#.VcEmRvkiST_
Conditions like this have many complicating elements for a definitive diagnosis, more than just what they look like in the instant of the photograph. So to help you perhaps narrow things down since you know how the vines have been all season and can look for more specific features, here is a very detailed list of grape diseases with excellent information about how they happen and what can be done: http://www.agr.gc.ca/resources/prod/doc/sci/pub/pdf/id_guide_major_diseases_grapes_e.pdf
In case it is black rot, here is some additional detailed information on that infection specifically: http://ohioline.osu.edu/hyg-fact/3000/pdf/HYG_3004_08.pdf
The good news is that there may be fairly simple ways to help reduce the incidence in future seasons. There are many readily available websites and print sources that discuss the many details of pruning and caring for grapes: they've been around for centuries and folks have invented many systems for them. But the basic line is that they benefit from very hard pruning in late winter. Although it seems hardly anything is left, they rebound with such exuberance once they get growing. I find that during the summer I also do some nipping and pruning to keep them a bit under control. So, have a look online and pick a pruning system that works with their location (on an arbor versus an espalier for example), and just be brave next winter in cutting them back!
Good luck!
