The Grapes

GROWING GRAPES IN VERMONT

Growing Grapes In Vermont

People often ask us if it is hard to grow grapes in Vermont. The answer we give, of course, is “No.” A wander down most any road or along any verge will offer evidence of wild grapes growing in profusion.

But, of course, what the questioners are really asking is if it is hard to grow wine grapes in Vermont.

Climatic Considerations
Vermont's winters require a hardy vine to make it through temperatures that can plunge into the -20˚ Fahrenheit range, and colder. Many familiar wines from France, Italy, California, Australia and Chile, for example, are grown from a species of grape known as Vitis vinifera, which is native to the Mediterranean and typically can't survive a Vermont winter. Cold temperatures like that can kill some vines.

Like any agricultural activity in the state, a lot depends upon preparation and field work, which can be controlled, and weather, which can't. Plenty of sun, rain when needed—but not too much, low humidity, no hail storms that can devastate the vines. It's not easy—no wine grapes are—but not as hard as it might have been. In fact, grape growing and wine making have been making dramatic inroads in Vermont, with vineyards and wineries located throughout the state, with demonstrated history of successful growing and the production of award-winning Vermont wines. More vineyards and wineries are being planned and developed and work done by the University of Vermont Extension Service's Cold Climate Grape Production has helped the state's grape industry to grow.

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While the new grapes show good resistance to common diseases and pests, serious vineyard Issues relating to typical Vermont weather remain. Early thaws followed by freezing temperatures that kill off the nascent buds, or early fall frosts that arrive before the grapes have fully ripened. Both can cause significant damage to the crop. Grapes have compound buds that actually contain three buds from which new growth originates. If the primary buds are killed off by a late frost, secondary buds will open and grow to replace them. If these are also lost to fluky weather, the tertiary buds will bloom, though with a vastly reduced crop. Mad River Vineyard has experienced some spring frosts that have taken out large numbers of both primary and secondary buds.

It’s necessary to look for grape varieties that are suitable for the conditions here and which bud out later to avoid the loss to frost of primary buds in the spring and ripen as early as possible in the fall to minimize cluster damage. One of the things that has allowed more and more grapes to be grown in Vermont has been the work done by some dedicated breeders, particularly those in Minnesota—people like Elmer Swenson, Tom Plocher, and the University of Minnesota’s grape breeding program. Hardy American vines, V. riparia, able to weather temperatures to -35˚F without damage, were crossed with varieties of V. vinifera resulting in grapes that offered excellent resilience while also bringing some of V. Vinifera’s balanced taste, with little or none of the herbaceousness or foxiness the riparia was sometimes known to display. Mad River Vineyard grows Marquette and Frontenac, both from UMinn, and Petite Pearl, a new grape from Tom Plocher.

Diseases and Pests

Diseases & Pests
Beyond the temperature considerations, grapes are also heir to a wide variety of diseases and pests. Wet weather early in the season and humid conditions through the summer can accelerate a variety of fungus infections including downy mildew, powdery mildew, botrytis bunch rot, black rot and anthracnose. Canopy management that involves shoot positioning and leaf pulling to keep the vines as dry as possible by exposure to the sun and open to breezes, as well as vineyard sanitation practices that eliminate sources of infection can help control these, but require a lot of hard work and many trips through the vineyard as the vines grow. Some vineyards take a pre-emptive approach and establish a regular spraying program. Fortunately, the cultivars that Mad River Vineyard grows that have been bred for cold hardiness also display elevated resistance to the afflictions of disease and pests when compared to vinifera or French-American hybrids.

In terms of insect pests, there are at least as many as diseases. In Vermont, phylloxera, grape berry moth, grape leafhopper, and the rose chafer can attack vines and can cause substantial damage to the crop. All require careful monitoring and constant inspection to stay on top of infestations.

However, Mad River Vineyard has found there is at least one insect that can be dealt with on a straight entrepreneurial basis. Japanese beetles love to visit us in late spring and early summer, ripping through the vineyard and reducing leaves to lacy ghosts of their former selves. The beetles are fairly large and easily seen. Joe’s approach has been to offer his grandchildren a penny bounty for each they bring in—it’s amazing how fast young ones learn how to count to large numbers and deal with financial transactions, while cleaning out the vineyard!

There are other, larger, pests that can do great damage to vineyards, especially later in the season . Birds and raccoons are known for developing a discriminating taste for grapes—attacking them just as they ripen to perfection. While we haven't yet been bothered by raccoons, Mad River Vineyard does cover its vines with netting in August before the grapes ripen. We remove them the morning of harvest to minimize damage by birds. In the past, Mad River Vineyard was a noted dining spot for the region’s robins, who fattened up nicely on the grapes.

Vermont does have some pests not likely to bother vineyards elsewhere, but we don’t suffer other problems. Growing wine grapes takes a great deal of patience, care and attention. We've carefully chosen the grapes that Mad River Vineyard grows to take advantage of their natural qualities as much as possible.