Q. I am trying to revive and old grape vine that has been neglected. It produces plenty of grapes but poor quality. It has been untrimmed and unsupported for years. The trunk is rotted half way through and splitting.
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| This was the only picture sent to me so there was not much to go on. |
A. This year just get it growing and don’t worry about producing any fruit. This requires pruning, irrigating and an application of fertilizer all done in February. We can discuss this at my grape pruning classes on Fridays and Saturdays offered on Eventbrite.
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| Great pruning classes offered on Eventbrite on Friday afternoon and Saturday morning.. |
Sign up for these classes here.
Remove excessive vine growth from the trunk. Select only 2 “arms” and leave only these attached to the trunk. Remove all the others. Cut these 2 arms back so they are each about 6 feet long. Support them so they are off the ground.
Next, locate smaller branches coming from the “arms”. Prune back these smaller branches coming from the “arms”, so they are 12 inches long. These are called “canes”. Observe where the fruit was produced on these canes.
Build a flat, dirt basin around the vine about 6 feet in diameter and 4 inches tall. Irrigate with about 30 gallons of water around the base of the vine and fill the basin with this water. Grapevine roots can be 30 feet deep or more. It will need this water to repair itself.
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| There is a flat basin constructed around the trunk of this grapevine that is about 2 foot in diameter. They are being watered with bubblers and a basin. I usually use drip irrigation when they are in production. Here the basin has broken and leaking water so it needs to be fixed. |
After the soil has been wetted, apply a high nitrogen fertilizer, manure or compost in the basin and apply it no closer than 12 inches from the trunk. Use about 2 cups of fertilizer, or a 5-gallon bucket of manure or compost. Water this in with 5 to 10 gallons of water. Be sure not to apply this fertilizer, manure or compost near the trunk.
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| This is granular fertilizer applied around fruit trees but you would do it the same way around a grape plant. Don’t get the fertilizer too close to the trunk. |
Water once a week in February to push new growth. You may or may not see flowering and berries depending on how much damage was done or how you prune it. Next year the fruit will be produced on growth from the current year. Where the fruit is produced on the cane will tell you if it should be “cane pruned” or “spur pruned”.
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| When Cane pruning grapes, leave last year’s growth with about 10 buds. |
Follow good grape pruning practices in 2020. This year just get it growing and observe where the fruit is produced. These efforts may not improve the eating quality of the grapes appreciably. If you still don’t like the grapes, replace the vine.
Note: I will post some information on my blog about how to prune grapes in a couple of weeks. Right now I would hold off pruning them until the weather begins to warm up.