Grapes (Vitis spp.) grow best when they are provided with a strong structure on which to twine. Not only does this help them grow healthy vines that aren’t stressed by unsupported weight, it exposes their leaves to light and creates room for their sweet fruit to hang down. Luckily, creating a trellis or holder for your grape vines isn’t difficult. Before getting started, you will need to know whether your grapes are an upright or drooping variety because this will determine the type of vine holder you make.
Choosing a Location
Grapes are most commonly trained to a central trunk with two lateral vines that extend from the trunk, one on each side. Grapes therefore grow well with extensive horizontal support. At a minimum, this means you will need to find room for a structure that is 8 feet in length for each vine. For best fruit production, grapes also require full sun, at least 7 to 8 hours per day. While their U.S. Department of Agriculture plant hardiness zone ranges depend on species, they usually grow well in roughly zones 5 through 8.
Vine Holder Construction
At a minimum, you will need two anchored posts, one on either end of the grapevine or grapevines, with tautly strung wires between them. The number of wires and their positioning depends on the grape and the type of trellis. To keep the wire taut, bury end posts at a 60-degree angle to the ground, and use brace wires to keep them sturdy. Brace wires are available at specialty stores. The tension created by the wire strung between the posts and the brace wire will provide sturdy wires on which the grapes can grow.
High Cordon System
The word “cordon” refers to the lateral vines that grow off of the grape’s main trunk, one on each side. With yearly pruning, these cordons are maintained so that they fruit most effectively each year. A high cordon system is most often used for grapes with a trailing or drooping habit, which means that their fruit-bearing canes will extend downward from the cordons. The highest wire, at about 5 feet, will support the arms, while an optional lower wire about halfway down the vine’s trunk provides additional support.
Low Cordon System
Although a low cordon system operates on the same principles, it is constructed a little differently. In this system, cordons are pruned lower on the trunk, supported on the main wire at about 3 feet, and then several wires are strung higher up. The grapevine’s canes then grow up into these wires, using them for support as they put out new shoots and produce fruit. Because the shoots will need more support than drooping varieties, you may want more like three support wires, each about a foot apart, for a total of four wires in all.
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