Pruning grapevine in summer?
October 17, 2017 3:44 AM Subscribe
I have a grapevine (for table grape) that is just starting its second summer. It has two main trunks and I don't want it to have any more, but it's put out a third one from just above the graft and it's going kind of crazy with leafing up and putting out side canes from this. Is it better to cut it off now or just let it do its thing and cut it back next winter when the vine is dormant?
I'm a bit concerned because in terms of total leaf area, the new trunk is bushier and more vital than the whole rest of the plant combined, so I feel like cutting this off would be a huge shock to the plant. The two existing trunks from last year are about twice the height of the new one, and they are putting out leaves and canes too, just not as many or as fast.
The vine also has a caterpillar infestation that I am getting under control. I'm only finding a caterpillar every two or three days now, but a lot of damage was done to new leaves and vine tips before I noticed, so the whole thing seems a bit fragile.
All the info I can find online about pruning grapevines suggests pruning heavily but seems to all assume you only prune once in winter each year rather than cutting off new growth near the end of spring as I'm thinking of doing.
I'm a bit concerned because in terms of total leaf area, the new trunk is bushier and more vital than the whole rest of the plant combined, so I feel like cutting this off would be a huge shock to the plant. The two existing trunks from last year are about twice the height of the new one, and they are putting out leaves and canes too, just not as many or as fast.
The vine also has a caterpillar infestation that I am getting under control. I'm only finding a caterpillar every two or three days now, but a lot of damage was done to new leaves and vine tips before I noticed, so the whole thing seems a bit fragile.
All the info I can find online about pruning grapevines suggests pruning heavily but seems to all assume you only prune once in winter each year rather than cutting off new growth near the end of spring as I'm thinking of doing.
Best answer: You can nip out the growing tip and also nip off the growing side shoots without removing the entire branch from the plant. For my grape vine I prune each side shoot from teh main stem to 5 leaves and tehn each sidebranch from those new growths to two leaves. I also prune away teh leaves that cover the grapes so they can try to ripen.
I've had various success with this but I did read this pruning regime in a book somewhere. I'm pretty sure my failures in ripening are more due to growing grapes in Yorkshire and not getting enough sun and warmth and not to do with the pruning. I'm sure you will have better luck than me with your more appropriate grape climate.
Mine is a slightly modified version of:https://www.rhs.org.uk/advice/profile?PID=286
posted by koolkat at 1:25 PM on October 17, 2017
I've had various success with this but I did read this pruning regime in a book somewhere. I'm pretty sure my failures in ripening are more due to growing grapes in Yorkshire and not getting enough sun and warmth and not to do with the pruning. I'm sure you will have better luck than me with your more appropriate grape climate.
Mine is a slightly modified version of:https://www.rhs.org.uk/advice/profile?PID=286
posted by koolkat at 1:25 PM on October 17, 2017
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the new trunk is bushier and more vital than the whole rest of the plant combined, so I feel like cutting this off would be a huge shock to the plant. The two existing trunks from last year are about twice the height of the new one, and they are putting out leaves and canes too, just not as many or as fast.
How thick has the new trunk gotten? If it's more than a couple of centimeters in diameter then I would leave it and prune in the winter. The existing trunks should put out plenty of new growth next year if they are well-pruned in the winter, especially if they aren't competing with a third trunk.
All the info I can find online about pruning grapevines suggests pruning heavily but seems to all assume you only prune once in winter each year rather than cutting off new growth near the end of spring as I'm thinking of doing.
During the growing season you can thin the leaves and trim any long lateral shoots (e.g. anything in danger of reaching the ground) to keep the plant reasonably compact and ventilated. This is especially important once you start allowing the plant to fruit.
posted by jedicus at 12:12 PM on October 17, 2017 [1 favorite]