How to Prune Grapevines and Canes

Growing grapes is a vastly rewarding experience for many gardeners. Like many other garden plants, it requires weeding, fertilizing and general care, but most importantly, grapes need pruning. Without pruning, grapes have a habit of overgrowing themselves, and producing more grape clusters than they can support. By pruning back your grapevine, you can boost its productivity and keep it healthy for seasons to come.

Things You'll Need

• Grapevines and canes
• Colored strips of cloth
• Pruning shears
• Scale

Instructions

1. Create a pruning schedule. Grapes are best pruned during dormancy, in late winter or early spring. Make note of the dates your grapes become active, and avoid pruning during those times. Select one month during which to prune, to avoid any excessively late pruning. Do not prune your grapevine during its first year, as it is establishing a healthy root system.

2. Prune the grape for a strong trunk. For a first-year grapevine, you will notice several stems growing from the root ball. Cut back all but the strongest, as this will serve as your grapevine's primary trunk. Do this only during the dormant period.

3. Prune the trunk for structure. Once your grapevine has reached your desired height, cut the trunk at the top to fit your supports. This encourages the grapevine to produce fruiting canes, rather than continue growing vertically.

4. Identify fruiting canes. Using strips of colored cloth, mark the fruit-producing canes you wish to keep. These canes should be at least 1 year in age, and will become your major sources of fruit-producing wood. It is not necessary to keep all your fruiting canes intact, keep only the best producers.

5. Prune the vines. Grapevines are produced as thin, draping branches off the fruiting canes. Using your pruning shears, remove all of these vines down to the cane.

6. Prune the grape canes. Proper cane pruning follows the rule "30 plus 10." This means that for every pound of cane you removed from the plant, you should leave 30 buds behind on the plant. Each additional pound you remove requires an additional 10 buds. As you begin removing growth from a cane, weigh it with your scale and count the number of buds you have left behind. Do not worry if you over-prune, your plant may experience slight underproduction for that year's harvest, but the grapevine itself will remain unharmed. The excess canes should be pruned back as closely to the trunk of the grape as possible, and should not be included in the "30 plus 10" rule.

7. Prune the renewal buds. Directly beneath the canes of the grapevine are small branches. Prune away all but two of them under each cane. These renewal buds will eventually replace the older fruiting wood once it no longer produces adequate harvests. Allow these buds to continue growing, but prune them back just enough so that they do not overtake the entire grapevine.

References

• "Iowa State University Extension: Pruning Grapevines"
• "Ohio State University Extension: Basic Principles of Pruning Backyard Grapevines"
• "University of California Cooperative Extension: Reasons and Rules of Pruning Grapevines"