Be aggressive in grape pruning

A grapevine in need of pruning. Photo by Darrell Blackwelder, for the Salisbury Post.

A pruned grapevine. Photo by Darrell Blackwelder, for the Salisbury Post.

By Darrell Blackwelder

For the Salisbury Post

February is an excellent time of the year to prune grapes. Pruning is an annual chore that must be severe to renew fruiting wood and to prevent vines from becoming tangled masses of unproductive and often diseased wood. Unfortunately, I have vines 5 years old or older that have never been under the knife. Overgrown neglected vines cannot be miraculously cured with a single pruning. Overgrown vines often take years to recover from extreme pruning, so in most instances it is often easier to start over with new vines correctly pruned and trained from the initial planting.

There are two types of grapes grown in Rowan County: bunch grapes like Concord and Niagara, and muscadine grapes (scuppernong) such as Noble, Carlos and Fry. Both have similar growth habits and but are pruned and trained differently.Pruning bunch grapes

It is important to concentrate on vine growth the first few seasons. New shoots need to develop from existing buds on young vines or vines that have just been planted. Choose the strongest cane and tie this to the wire with a piece of string. Remove the side shoots and let one develop into a main trunk. If your main shoot does not make it to the top wire the first season, prune the shoot back hard to stimulate faster growth next season. The root system will be well established and next season's growth should be rapid. Bunch grapes grow best on a two-wire trellis system, similar to a clothesline.Select canes the second year to grow laterally along the wire. Prune back and leave 8-10 buds. Tie canes to the wire with soft cloth strips or string. Never use twist tie wires. The wire injures canes by cutting into rapidly growing canes.

All grape vines must be pruned annually to prevent alternate or biennial bearing as well as facilitating spraying and harvest.

Mature vines have three steps in pruning. The first step is to prune last season's growth, removing all canes that grew the previous summer to 4-5 inches in length. These spurs should be about 6 inches apart on younger vines.As the vine matures, the vines develop clusters of spurs that need to be thinned every three years. Spurs should be trained to point downward toward the ground. The second step is to remove suckers or shoots from the trunk and damaged or dead laterals. A new cane must be trained (above the graft) to replace any removed laterals. The third step is to remove all tendrils that attach themselves to the trunk or fruiting laterals.

Properly pruned bunch grapes look terrible. Canes most likely will bleed excessively and look butchered. However, bunch grapes will never produce a superior crop without severe pruning.

Pruning muscadine types

Muscadine grapes (scuppernongs) are pruned differently than bunch grapes. Most home gardeners like this type of grape because it is much easier to train and prune on an annual basis than bunch grapes.

Muscadine grapes are trained the same way as the bunch grape for the first two growing seasons. A single wire trellis system also works best for this type of grape.

Lateral canes trained along the wire trellis will remain as a permanent cane. This permanent lateral may grow to be very large, up to 2 inches in diameter. Many shoots will develop along this lateral. Each cane or shoot is cut back annually, leaving 2-3 buds per spur. Approximately 20 spurs should be retained for each 10 foot permanent arm. The location of the spurs is not important in muscadine grapes. Correctly pruned laterals have a hair brush effect, with spurs pointing up and down. These spurs will produce the fruit and new canes each season.

This type of vine is very easy to prune and maintain once permanent laterals are established. It is imperative that both muscadine type and bunch grapes be severely pruned each year to control growth, increase fruit set and keep vines healthy.

Darrell Blackwelder is an agricultural agent in charge of horticulture with the North Carolina Cooperative Extension Service in Rowan County.

Darrell Blackwelder

Extension Agent-Horticulture

Rowan County Center

North Carolina Cooperative Extension

2727 A Old Concord Road

Salisbury, NC 28146

704-216-8970

http://www.rowanmastergardener.com

http://rowan.ces.ncsu.edu

www.rowanextension.com