I have a few old grape vines that I'm trying to re-cultivate (the previous owners let them go wild). I was doing pretty well until we went away for a couple weeks and then got tied up with work. Next thing I know, a majority of the foliage is covered in omnivorous leaf roller. This is our 3 year on the property and never had them before. They caught us completely by surprise! The big Question.... 1. Do I cut off all the foliage and try to break the cycle? 2. Do I spray, knowing they're hard to kill in the cocoons? 3. Do I leave it and try to catch it early next year? 4. Do I cut it all back and try to start over next year? 5. All of the above! The little Question... The plants are atleast 10-20 years old, Concord (I think). Produce a decent amount of grapes since I've thinned them this year. But the vines are all over, some 20+ ft. of woody stem winding back and forth along the ground and then trellis. They're more for novelty than expecting a serious harvest. We like the fact that these were planted by the nice old lady that we bought the house from. I'd hate to have to start over. Does anybody know if I cut them back hard - just to normal lenth truncks, will they come back? If so, when? Thanks for your input.
For now just spray the grapes monthly and pick the coccoons as best you can. If there are grapes on the vine you might wait till after you have harvested them before beginning to spray. Grapes are pruned during the winter or dormant season. You can prune and reshape the vine then. Grapes produce on year old canes so you may lose a few grapes the first year after pruning but your vines will be healthier and it takes less water if they don`t have all the extra leaves and canes to feed. Start early in the spring with your spraying program before the critters attack and spray monthly. You can also thin the leaves a bit during the growing season. Perhaps the insects will find it less appealing without all that lush foilage.
Thanks for the quick response Mart. So with the pruning, if I do a hard pruning back so the trunk is a couple feet long, it shouldn't kill the plants, right? I understand I may not get any grapes next year, but I'd rather do what I need to have a nice looking trellis and healthier plants in years to come. The plants are right along the driveway and are more for looks than anything else.
I wouldn`t prune quite that hard. Pick two canes on each side of the main trunk to leave as is. And then prune back all the wild growth. On the ones that you leave you can trim them back a bit as well. This should give you a good vine that you can control without damage to the root system. Like the way they do at a vineyard. They have the main trunk and they have laterals for the grape production. Hopefully, the pruning will take care of the leafrollers. Then a spray schedule should keep them from returning.
Good Luck with them. I make a lot of grape jelly with mine as well as a bit of wine vinegar for salads. Too hot here for making wine without some way to cool the juice for a while. But the vinegar is great. Better than the stuff you get at the market. Let me know how they do.
