Q.I Have A 20 Year Old Grapevine Which Only Produces 1 Or Two Bunches Of Grapes If I’m Lucky. Should I Now Replace It With A New
one It is planted on a south facing wall which is part of my garage. I prune it to 2 buds in the dormant season . I have been advised not to feed it as all the goodness will go to producing leaves.I would be grateful for your advice please .
Certified GKH Gardening Expert
Likely, since it doesn't get fed, it is needing nutrients.
The best thing to do will be to test the soil. This will tell you the pH of the soil and nutrient content. With these two pieces of information, you can amend your soil back to within the proper ranges.
Feeding with an all purpose without testing the soil can lead to a nitrogen build up. This will halt fruiting and produce lush vegetative growth. But deficiencies in potassium and phosphorus, and even sometimes a deficiency in micro and trace elements will cause fruiting issues.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
This article will help you to feed grapes, properly:
https://www.gardeningknowhow.com/edible/fruits/grapes/how-to-fertilize-grapes.htm