Gray Barn Green Thumb Guide
Favorite Grape Varieties
Almost all grapes are self-fruitful and do not require pollination from another variety to bear fruit. The following grapes are adapted for the Pacific Northwest climate, having a moderate summer heat requirement and hardiness for our zone 8.
Buffalo Seeded black fruit with spicy flavor. Excellent mid-season concord-type grape. Productive and good for table, juice or wine. Can produce a second crop if subjected to an early frost.
Canadice Small, red, seedless, early maturing, with sweet slightly foxy flavor.
Himrod Seedless white fruit with spicy flavor. Good for fresh eating. Very vigorous, suited to arbors. Hardy to -15˚F.
Lakemont Seedless white fruit with mild flavor. Very productive. Fine table grape, keeps well in cold storage.
Interlaken Firm seedless green or yellow grape with fruity flavor. Excellent for fresh eating. Best for raisins in cool summer areas. Ripens a week earlier than Himrod. Extremely vigorous vine. One of few that matures in the coolest areas of Pacific Northwest.
Vanessa Firm, seedless red grape with fruity flavor. Resists cracking. Good replacement for European variety ‘Flame’ in cool summer areas. Use for fresh eating or raisins.
Grapes need full sun and well-drained soil. A Southern or Western exposure is best. Provide a sturdy arbor, trellis or fence to support the heavy vines, and plant about 1 ½ feet from the support. Space grapevines 8-10 feet apart. Fertilize annually in the spring, but beware of giving too much nitrogen which may cause the plant to be overly vegetative at the expense of fruit production.
Grapes change color long before they are fully mature, so it’s possible to pick them before they have reached their peak in flavor, size, and sweetness. 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.
Pruning and Training Hardy Varieties (From the University of Minnesota Dept. of Horticulture)
Prune vines when they are dormant, removing about 90% of the wood that grew the previous season. Although there are several systems for training grapes, the four-arm Kniffen system 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. 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.
Washington State Extension http://cru.cahe.wsu.edu/cepublications/eb0775/eb0775.html
The Berry Growers Companion by Barbara Bowling, 2005
The Western Garden Book of Edibles, Sunset Publishing, 2010