Choose the two laterals that are closest to the wire, tie to the wire, and prune to buds. Tie the main stem to the wire and stake, and cut just above the side laterals C.
During the summer , train the new shoots up to the next wire, and remove any new shoots that sprout from the root area or lower trunk. Grapes bear fruit on the green shoots that arise from one-year-old canes. Pruning is based on producing fruit in the current season, and renewing young canes for the next year. The old canes that produced fruit this season will not produce again. There are several methods used in pruning established grapevines.
Cane pruning is the usual system in climates like ours where heat units may not be high and vigorous vines can shade the fruit. In this system a permanent trunk is established, and every year new canes are selected from the head of the vine, where trunk and wire intersect. One or two canes on either side, each buds long , are selected and tied to the wire, and all other canes cut out.
Choose canes that are about the thickness of your little finger, that come out as close to the head as possible, and that have buds fairly close together. Try to avoid large thick canes with buds spaced far apart.
Also leave one or two spur canes, cut to two buds each. In our climate conditions, too often the upper level shoots are so vigorous that they shade out the lower level, so the kniffen system is not much used.
Selection of a training system definitely determines how you would prune your grapevines. Many gardeners prefer the high cordon system Figure 1a since it is relatively simple to establish and maintain where others like to incorporate a grape arbor into their landscape. Young vines are carefully trained to either one or two trunks. The fruiting area is established as either head-trained Figure 1b with canes hardened-off shoots , permanent cordons horizontal arms with dormant canes pruned back as spurs, or a fan-shaped arrangement on top of a four-post arbor structure.
In a cane-trained system, new canes are laid down each season. Grapevines under this system are generally head-trained at the top wire. New shoots that are produced during the growing season harden-off as canes with a reddish-brown color and will be approximately pencil size in diameter. Two of these canes are selected and tied down to the top wire; one cane is laid down in each direction.
Canes can be tied using pieces of cloth, twist ties or plastic stretch tape. Buds are counted and the number is adjusted according to the desired fruit load. Cordon-trained systems are different in that new spurs are established each growing season as one-year-old canes and are pruned back to three to four buds per spur.
When growing grapevines on an arbor, the fruiting wood may be either one-year-old canes or spurs that are attached to cordons positioned on top of the arbor. Pruning practices vary a great deal based on the type of grapes grown.
American and French-American hybrid varieties are more commonly grown in home gardens than Vinifera varieties since they are more winter hardy and disease resistant.
Vinifera varieties tend to be grown by more advanced grape gardeners. American, French-American hybrid, and Vinifera varieties differ in the amount of fruiting wood that is produced annually. American cultivars tend to have the greatest amount of vegetative growth followed by French-American hybrid varieties.
Vinifera varieties have the least amount of foliage. Canes are pruned long during the winter, then once budbreak occurs the canes can be cut again to the desired number of buds. This effectively delays budbreak of the buds near the base of the cane by several days. Spur pruning. Growth of spur and buds during the growing season, and the resulting spur the following season. Varying the extent of dormant pruning is one way to influence cropping level.
The term bud count also node count or node number is used to describe the number of dormant buds retained at pruning. Generally, bud count considers only the buds having clearly defined internodes in both directions Wolf and Poling, , thus basal buds are not included in the count. Basal buds , sometimes referred to as noncount buds, are not included in bud counts because frequently they do not produce shoots , and if they produce a shoot it is often unfruitful.
Grape growers often prune vines with the intent to achieve a balance between fruit production and adequate, but not excessive, shoot growth. Increasing the bud count increases the number of shoots, which, if excessive, can lead to a crowded canopy and increased shading. Cropping levels are also increased when bud count increases, and the vine may not be capable of fully ripening high crop levels despite the increased shoot number.
At very high bud counts the vine compensates for the large number of shoots with shorter shoot growth and fewer clusters per shoot Coombe and Dry, Excessive pruning —- retaining too few buds -— leads to an undercropping situation. Removal of fruitful buds reduces crop load, but it also eliminates primary shoots. The consequence is often an excessively shaded canopy that provides a poor fruit-ripening environment. Because pruning directly influences the number of shoots and the potential crop level, it is often the most significant annual management practice affecting vine balance.
Consequently, the concept of vine balance is the basis of most pruning strategies. The bud count is based on an estimate of the weight of extraneous canes removed by pruning —- the pruning weight. RHS Christmas gifts. Help us achieve our goals Make a donation. Join the RHS today and support our charity Join now. Save to My scrapbook. Tucking shoots under a wire.
Quick facts. Suitable for Indoor and outdoor grape vines Timing Major pruning is in early winter; training in spring and summer Difficulty Difficult. Jump to Suitable for When to prune and train Putting up supports The pruning systems Problems. Suitable for Grapes grown for wine and dessert grapes outdoors are usually pruned and trained according to the Guyot system Grapes grown against walls, fences, pergolas and those grown in greenhouses are usually pruned and trained according to the rod and spur system Grapes grown in containers are usually trained as standards.
When to prune and train The main pruning time is early winter late November or December. Putting up supports No matter where you grow your grape vines, you will need to put up some sort of support system. The pruning systems The Guyot system : This form of training has either one or two fruiting arms growing from the main stem single or double Guyot accordingly.
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