WW-01103 Reviewed 2008
|Emily Hoover, Extension Horticulturist
Peter Hemstad, Assistant Scientist,
Department of Horticultural Science
Copyright © 2013 Regents of the University of Minnesota. All rights reserved.
Grapes can grow in almost any part of Minnesota if varieties adapted to our cold, dry winters and short growing season are chosen.
Grapes need full sunlight and high temperatures to ripen, so plant on southern slopes, the south side of windbreaks, or the south sides of buildings. Avoid northern slopes and low ground since these will be cooler throughout the growing season, delaying ripening of the fruit. Choose deep, well-drained soils to avoid standing water in the spring and encourage early growth.
Plant in the spring as soon as the soil can be worked. Use healthy plants with well-developed root systems. Space the plants six to eight feet apart. Before planting the vine, remove all canes except the most vigorous one. Trim off any broken or excessively long roots.
Dig a hole large enough so you can spread the root system out without bending the roots. Plant vines at the same depth as in the nursery. Do not plant too deeply. Spread the roots and cover them completely with soil. After planting, shorten the remaining cane to two strong buds. Each bud will develop into a cane.
The following is a partial list of varieties. These varieties were chosen because of their winter hardiness and/or quality.
In the mid-1970s, this white French hybrid variety was much more widely planted across the eastern United States and in Minnesota than it is today. Although an early ripening and fairly hardy white wine grape, growers were disappointed with its mediocre wine quality and susceptibility to both black rot and splitting at harvest time.
For decades, this cross between Concord and a wild Vitis riparia vine was the most widely grown grape in Minnesota. Beta’s popularity arose from extreme hardiness and acceptable juice and jelly quality. At present, there are newer varieties (such as Valiant) which may be as hardy and are certainly higher in quality. Beta wine tends to be quite poor, but jelly is very flavorful.
An old variety from the University of Minnesota, Bluebell is currently being rediscovered by growers and nurseries. It is recommended for those interested in a high quality labrusca-type grape for fresh eating, juice, or jelly. It has sufficient hardiness to be left on the trellis over winter in the southern half of the state. Bluebell is resistent to most diseases.
This is a relatively new, pink, seedless variety from the New York State Experiment Station at Geneva, New York. Worthy of trial (with winter protection), but not an outstanding performer to date.
Concord is the most widely planted grape east of the Rockies, and it popular in Minnesota, too. Although considered “very hardy” in other states, it is not dependably hardy in Minnesota. This fact, together with its late ripening date, make it a relatively poor choice for our area. Alternatives include Bluebell, Fredonia, Van Buren, and Worden.
De Chaunac is a French hybrid wine variety that has made some palatable red wines in Minnesota. Although a heavy yielding cultivar, it is not grown as extensively as Foch or Millot, primarily because the latter two are earlier ripening. De Chaunac has a large cluster and should be cluster thinned to avoid overcropping.
Elmer Swenson of Osceola, Wisconsin, has been breeding hardy grapes for over 40 years. His first two introductions, Edelweiss and Swenson Red, were released jointly with the University of Minnesota. Edelweiss is a large-clustered, white variety that has good quality as a table grape as long as it is picked promptly. When completely ripe its labrusca flavor becomes too strong for many palates. Edelweiss is also sometimes used for wine, but again, it should be harvested early. This variety has proven to be less than reliably hardy in central Minnesota, so winter mulching is recommended. Its young shoots tend to be unusually brittle so extra care is needed when tying these vines.
Elvira is a white variety of Vitis labrusca and Vitis riparia parentage. While it is hardy enough to be grown without winter protection on good sites in Minnesota, Elvira’s wine has a foxy flavor and is frequently acidic.
Esprit is a relatively new white wine variety developed locally by Elmer Swenson. To date, late ripening and marginal hardiness have discouraged widespread planting.
This French hybrid grape is the most widely grown variety in Minnesota and has frequently produced some good quality red wines. In addition to being very early ripening, Foch is one of the hardiest French hybrids. Unfortunately, in Minnesota it still requires winter protection for consistent cropping. The small black berries can be very attractive to birds and in a rich soil this vine can frequently have excess vigor. As its clusters are small, it should not be pruned severely.
Fredonia is a blue labrusca table grape. It is similar to Concord except that it is earlier ripening, has larger berries, and its quality is a bit lower. In Minnesota, it should be laid down each winter for good production.
This variety from Geneva Experiment Station in New York State is a white seedless table grape descended from the familiar Thompson Seedless cultivar. Although its flavor is outstanding, Himrod’s berries tend to be small and its clusters are frequently straggly. It is particularly vulnerable to winter injury.
Kay Gray is one of the Swenson varieties widely planted in our region in recent years. Its virtues include early ripening, low acid levels, disease resistance, and good winter hardiness. On the negative side, its clusters tend to be small, and winemakers have sometimes experienced difficulty making Kay Gray into a high quality wine.
Another white Swenson variety, La Crosse has shown the potential to make some pleasant wines that reflect its Seyval parentage. The vines should be covered for best results.
Leon Millot is a sister seedling of Foch and is very similar to it in many ways. By comparison, Millot is slightly earlier ripening, more susceptible to powdery mildew, less hardy, and may make a higher quality red wine.
|Aurore||France||Tender||White||V. Early||W, T|
|Bluebell||U of M||Mod Hardy||Blue||Early-Mid||T, J|
|Edelweiss||U of M||Tender-Mod||White||Early-Mid||T, W|
|Elvira||MO||Mod Hardy||White||Early-Mid||T, W|
|Kay Gray||Swenson||Hardy||White||Early||W, T|
|St. Pepin||Swenson||Tender-Mod||White||Early-Mid||W, J|
|Swenson Red||U of M||Tender-Mod||Red||Mid||T|
|Van Buren||NY||Tender-Mod||Blue||Early||T, J|
|Worden||NY||Mod Hardy||Blue||Early-Mid||T, J|
|Key for Principal Uses:||Key for Hardiness:|
|J = Juice or Jelly
T = Table
T* = Seedless
W = Wine
|Tender = Requires winter protection everywhere in Minnesota.|
Tender-Moderately Hardy = Can be grown without protection on especially good sites in southern Minnesota.
Moderately Hardy = Can be grown without protection on good sites in central Minnesota.
Hardy = Can be grown without protection throughout the Southern two thirds of the state. Will require protection in northern Minnesota.
Very Hardy = Needs no winter protection in Minnesota.
St. Croix is the one red wine variety that Elmer Swenson has released to date. It is similar to his white variety, Kay Gray, in that it is hardy, low acid and disease-resistant. It is still too soon to judge its wine quality potential.
Yet another Swenson introduction, St. Pepin is a sister seedling of La Crosse. St. Pepin makes a fruitier wine and has the disadvantage of being pistillate (it requires cross pollination with another variety). Unlike many wine grapes, St. Pepin is also pleasing either as a table grape or for juice.
Seyval is perhaps the premier white wine variety in the eastern United States. It is also commonly grown in Minnesota, although it does not always ripen adequately here. It requires both cluster thinning and thorough winter protection to perform well.
Swenson Red is a high quality seeded table grape with large crisp berries. Its pleasant mild flavor is closer to that of vinifera than labrusca grapes. This variety is a result of Elmer Swenson’s breeding work, and like Edelweiss, was a joint introduction between Swenson and the University of Minnesota. Swenson Red is susceptible to downy mildew and is not hardy enough to be dependable in the Twin Cities area without winter protection.
A cross between Fredonia and a wild Vitis riparia vine resulted in this recent introduction from South Dakota State University. Valiant is a very hardy blue table grape that ripens dependably throughout much of the region. It makes good quality juice and jelly, but is unsuitable for wine. As a table grape, its biggest drawback is the small size of both berry and cluster. It is susceptible to mildew.
Van Buren is another of the numerous blue labrusca-type varieties useful for dessert, juice, or jelly. Its hardiness in Minnesota has yet to be thoroughly tested, but its earliness and high quality make it deserving of further trial.
The characteristic that separates Vanessa from other eastern seedless introductions is its crisp texture. Vanessa has attractive, medium-sized clusters that are well filled with red berries. Its taste is mild, but its texture is superior to other commonly available cultivars. Like the other seedless types, Vanessa does require winter protection in Minnesota.
Vignoles (or Ravat 51) is a low yielding French hybrid variety that has the potential to produce outstanding white wines under favorable conditions. It has not been widely tested in Minnesota, but appears to have promise. Additional fungicide applications may be required to control bunch rot in a wet year. Extra buds should be left when pruning to compensate for its small cluster size.
This Concord seedling has proven to be one of the most dependable Eastern labrusca varieties in Minnesota. It is not only more winter hardy than its parent, but earlier ripening. The fruit resembles Concord except that its berries are more pointed, and Worden’s flavor is more subdued. In a wet year, the tightly packed berries have a tendency to crack.
Although vines often are allowed to grow at random, sprawling over the ground during the first season, it's best to train the stronger of the two canes that develop from the plant to a strong stake, five to six feet tall. Remove any suckers growing from the base of the canes. Remove the weaker cane in March. If neither cane is three feet long, cut the plant back to two buds again the second year.
Apply nitrogen two weeks after planting at a rate of 10 lb of 10-6-4/100 ft of row. Reapply the same rate annually in early spring, right before growth starts. Fertilizer can be applied to a single plant at a rate of 1 lb/plant. Have the soil tested every three to five years. Do not apply fertilizers containing herbicides (such as some lawn fertilizers) in or near the grapes. Four to six inches of mulch may be applied to help control weeds and conserve soil moistures.
Although there are several systems for training grapes, the four-arm Kniffen system (Figure 1) is the most simple for varieties that do not require winter protection. In this system, two horizontal wires are stretched between posts to support the vine. The bottom wire is 36 inches and the top wire is 60 inches above the ground. The young vine is tied to a stake and, as it grows, to the two wires. This ensures a straight trunk for the mature vine.
Begin training after the vine reaches the first wire. Remove all shoots between the wires and cut back shoots along the lower wire to two buds (Figure 1B).
The mature vine has four to six canes (each with five to twelve buds) and four to six renewal spurs (each with two buds).
When pruning, keep in mind that fruit is produced on the current season’s growth, that in turn grows from last season’s wood. Heavy pruning provides the best fruit. Light pruning result in large yields of poor-quality fruit; very heavy pruning produces too much vegetative growth and very little or no fruit. Table, juice, and jelly varieties can have 40 to 60 buds per vine, but wine varieties should have only 20 to 30 buds per vine after pruning.
Figure 1. The four-arm Kniffen system. A. The vine is tied first to a stake and later, as it grows, to the wires. B. Branches should be removed (a) or cut back to two buds (b) along the lower wire. C. A mature vine before pruning. D. The same mature vine after pruning. Sp = renewal spur; c = one year old fruiting cane. Fruit clusters will form on shoots emerging from buds on these canes.
In varieties that require winter protection, prune the vine to a single horizontal trunk that can be removed from the trellis (Figure 2).
To over-winter the plant, bend the trunk down and cover it with six to eight inches of soil or mulch. Uncover approximately mid-April, or as soon as frost is out of the ground. Then lift the vine and tie it in place on the trellis. As shoots grow from the trunk, tie them in an upright position to the upper wires. In the fall, when these shoots have matured into canes, cut them back to short spurs containing one or two buds each.
You can increase the trunk’s length by bending down the cane farthest from the base of the plant. In this manner, one to two feet of new trunk is added each year until the trunk reaches the desired length of six to seven feet.
Prune old and neglected vines in stages. Select a sturdy cane originating near the base of the plant. Cut it back to three to four feet. After this cane completes its second growing season, cut off the old trunk just beyond the attachment of the renewal cane. Old, neglected, or improperly pruned vines usually have too much wood. When pruning, cut as much of the old wood as possible. This encourages the growth of new wood near the main body of the vine.
Grapes change color long before they are fully mature, so it’s possible to pick the clusters before they have reached their peak in flavor, size, and sweetness, if berry color alone is used as a guide. For best fruit, taste the grapes first to see if they are ripe. If they aren’t, wait for optimum quality to develop. Grapes will not improve in quality once they are harvested.
It’s easy to propagate grapes from cuttings. Take sections of the canes from healthy, moderately vigorous vines while they are dormant. This can be either in late fall or in early spring before growth starts; early spring is preferred because once the cuttings have leafed out and formed roots they can be placed outside, first in the shade, and then planted out in the vineyard. Cut the sections directly from the vine or from brush that has recently been pruned off. Make cuttings three nodes long with the bottom cut (the portion that will form roots) just below the bud or node and the upper cut at an angle of about 45 degrees, ¾ to 1 inch above the bud or node (Figure 3).
Plant cuttings as soon as possible after they are made. Place the cuttings with the second bud from the top at soil level and cover with loose soil. Rooting will be enhanced if the cuttings are placed in a humid environment. After rooting has taken place, move the cuttings outside if the temperature remains above freezing. Protect new plants from direct sun. After the cuttings have adjusted to the outside environment, they can be planted in the vineyard. It is important to not let the cuttings dry out during this process.
Birds can be a nuisance in grapes. The only protection is to place netting over your grapes.
Grapes are extremely sensitive to the fumes of 2,4-D, which is widely used to control dandelions in the lawn. Severe exposure results in deformed leaves and destroyed flower clusters. Gardeners who use 2,4-D around their grape plants after they have leafed out may find it impossible to grow grapes.
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