Concord grapes provide a rich grape flavor in juices, jams and wines. These grapes bear dark-purple skin and slippery flesh with seeds inside. Popular among homeowners for their cold tolerance, Concord grapes do need regular care in order to perform well. Since the vines are so vigorous, they will take over the garden if not tended.
Concord grapes need full sun in order to grow properly. The grapes also need to be provided with a trellis system in order to grow. Gardeners can place the grapevine near an arbor and allow the vine to grow up the arbor, or they can create a trellis system. Common trellis systems allow the vine to creep along one to two wires, called arms. There are several trellis systems that home gardeners can adopt, according to the University of Missouri (see the Resources section of this article).
Concord grapes are among the most cold-hardy grapevines. Concord grapes will experience frost damages at temperatures of minus 10 to minus 20 F. To protect Concord grape plants from potential winter injury, prune the vine back to a single step and wrap the stem with burlap. Unlike plastic, burlap is breathable so the grapevine will not smother in its wrapping. Many gardeners will not need to take this precaution since they will not experience such low temperatures.
Concord grape plants need regular water in order to grow and produce fruit. Established grape plants can get some of this water from rain, but young plants need regular irrigation regardless of weather. For your Concord grapevines, water the soil when it becomes dry until it gets saturated with water. Water young grapevines in this manner all the time, and mature or fruiting vines only when you experience low rainfall in your community.
Concord grape vines should be fertilized annually to keep the plant healthy and productive. Oregon State University suggests 10 oz. of 10-20-20 fertilizer per vine, applied once annually, in the spring. Scatter the fertilizer on the soil near the base of the plant, then water the ground to work the fertilizer into the soil.
Gardeners must prune annually to keep their grapevines healthy, and Concord grape plants need to be pruned during the dormant season, from January to March. According to Oregon State University, 90 percent of the growth must be pruned annually. Gardeners must prune away growth from the main shoot and prune the fruiting arms back to seven or eight buds a piece.