A Bunch of Great Reasons to Grow Grapevines
Thursday, March 23, 2006
The garden grapevine is an old-fashioned plant not much favored anymore. Your grandpa used to grow it because it reminded him of boyhood on the farm. But the farm is too far removed from most Americans today, so that yearning has past. This is a shame because the right grape variety with a bit of care can bring beauty, shade and fruit to patios big and small.
Its neglect may be down to the fact that the workhorse, the venerable Concord grape, makes a juice many find palatable but as a table grape is a bit of a spitter with its astringent skin and large seed.
Many better-tasting varieties of American grapes have been introduced since the Concord came along in the mid-19th century, including several varieties developed in breeding programs in recent years at the University of Arkansas and Cornell University.
The storied grape of the Old World, the vinifera, yields all the fabulous and famous varieties for winemakers, including chenin blanc and chardonnay, but is tough to grow in hot, humid regions like ours, where fungal diseases abound. Early Americans, Thomas Jefferson among them, spent fortunes watching their vinifera vineyards shrivel and die.
Southern muscadine grapes produce large, single berries and are disease free, but here they are only for the brave of heart: They grow vigorously (the advice is to plant them 20 feet apart) and are marginally hardy. You may also need a second vine for pollination, depending on variety.
American and American hybrid grapes are a great compromise between the muscadine and the vinifera grape -- they respond well to basic care and an attentive gardener. They make great decorative vines for the garden. As plants to cover and shade patio arbors, they are much less trouble than wisterias, which need continual pruning but rarely get it. Like wisterias, grapevines provide swift coverage in a way that climbing hydrangeas and clematis do not.
Grapevines need good drainage and full sunlight. You may find wild grapes growing in the woods, but their object is to use trees to get to the light.
Even sturdy grapes such as the improved hybrids can get powdery mildew, an unsightly mold that shows up in mid- to late summer. But the bigger problem is a destructive fruit mold named black rot. Both can be prevented with spraying, and organic, copper-based sprays can be used.
The most tiresome pest of the grape is the Japanese beetle, which can arrive in large numbers in July and turn the leaves into skeletons. This can be a highly localized phenomenon, and the beetle can be picked off and destroyed. Grapevines are so vigorous that even a badly attacked vine can produce fresh growth.
Vines can be trained on wires or rail fences as well as arbors, but when grown against solid structures such as walls or privacy fences, the foliage is more prone to fungal problems because of poor air circulation.
The key to healthy, fruitful vines is winter pruning. Once the trunks have been trained in the first year on wire or arbors, the lateral branches should be cut back each winter to one or two pairs of buds. If you don't do this, the fruit will get small, the vines will become a twiggy mess, and parts of the vines will shade out others, resulting in dieback. "The key is never to skip a year in pruning," said John Clark, a grape hybridizer and horticulture professor at the University of Arkansas.
If you want an example of how useful a vine can be, visit the U.S. Botanic Garden's Bartholdi Park at Independence Avenue and First Street SW. On a 5-by-12-foot arbor, gardener Robert Pritchard has grown a single plant of the Mars variety. It covered the arbor after two years, he said, and now, after eight seasons, sports a handsome, silver flaking trunk. He prunes it in midwinter, before the sap rises.
Remarkably, he doesn't spray, either against mildew or black rot, "and I haven't had any problems," he said. The beetles are plucked by hand and dispatched. "It's a pretty good-sized vine, yet this can be accomplished by hand," he said. Park users help themselves to the grapes, but they often take the berries before they color up and are fit for eating. Clusters that are high and out of reach sweeten into grapes that are "just heavenly," Pritchard said. Proving once more that in the garden, patience brings great reward.