Growing Grapes in Your Backyard
Designing the arbor to facilitate vine management and maximize production can be both aesthetically pleasing and functional. Build the frame of the arbor using very strong timbers and sound fittings. Use large eye-screws and thick wire, and add a turnbuckle to enable tightening of trellis wires by turning the screw.
In deciding how many vines to use on an arbor, consider that in many gardens grapevines grow excessively. Shoot growth is greater on vines that are given inadequate space. However, vines given too much space may become stunted if the energy of the vine is directed into too many clusters. A healthy vine will take up a minimum of about 50 square feet of arbor space, and vigorous vines should be given 75 to 100 square feet or more.
Determine where the cordons will be created, and attach eye-screws and wires where cordons will be. Cordons should be about 5 to 7 feet apart where more than one cordon will be used. In one scenario, one cordon per vine may be used to span the width of the arbor, so on a 36 x 8-ft. arbor, 6 vines could be planted 6 ft. apart along one long edge, beginning 3 ft. in from the ends. If high vigor is expected, three vines could be used instead, each with two cordons that are spaced 6 ft. apart.