Depend on the variety. Not all grapes are hardy in cold winters. Varieties listed are adapted to cold weather. If planting in a warmer climate, consult your County Extension agent for recommended varieties.
Acidity (pH) Tolerance
Grapes are tolerant to a wide range of pH conditions depending on variety.
Salinity (Ec) Tolerance
Depends on variety
Grapes are not heavy feeders and do not need much fertilizer after they are well-established. Too much fertilizer stimulates wood and leaf growth rather than fruit production. Moderate amounts during the first and second years after planting will help stimulate young plants to size up for earlier fruit production.
Place 1/4 to 1/2 cup of 16-16-8 fertilizer 2 to 3 inches deep and 10 to 12 inches from the plant when planting and again in March of the second year.
After the first two years, avoid excessive fertilizing which produces bountiful green growth at the expense of fruit production. Unless a soil test indicates the need for phosphorus or potassium, use only nitrogen fertilizer. Do not apply unless the plant leaves yellow during the early part of the season or if the plant is showing poor cane growth. Late feeding during the ripening period can force excessive growth which will spoil the fruit.
Grapes have deep root systems so don't need the same water schedule as shallow rooted plants like lawns and garden vegetables. Once established, grapes need little irrigation. Place the plants where they can be watered heavily and deeply, but infrequently. Heavy clay soil tends to hold water around the roots, which has the same effect as over watering. Too much water can trigger iron chlorosis.
Plant Development and Care
Grapes should have some sort of support. Build a trellis with two wires, one about 18 inches above the other after planting, or use a fence, lattice trellis, or arbor as a support for grapes.
Support is optional the first summer, but essential after that. Prune off all but the strongest stem and tie it up to a post to develop into a strong trunk the second year. The third year, select four side branches, two on each side of the trunk and train them along wires about 18 inches apart.
Each year thereafter, the plant should be pruned heavily. Nearly 90 percent of the previous year's growth should be removed each year. Four strong canes should be selected from last year's growth, and trimmed back to include 10 or 12 buds to grow and produce in the upcoming season. Four more canes are selected as renewal spurs. These should be cut back nearly to the trunk leaving 1 or 2 buds to grow strong canes for next year. All else, including last year's wood should be removed to the trunk.
Grapes can be pruned whenever the gardener has the time. Canes can be removed in the fall for Christmas wreaths, but pruning is ordinarily performed in March or early April before the buds begin to swell.
The pruning cuts will continue to drip sap from their wounds until the plant breaks dormancy in the spring. This weeping is not harmful in any way to the plant. Sap in plants is not limited in supply like blood is for animals. It is primarily composed of water which is continually supplied by the roots.
Grapes aren't heavy feeders and do not need much fertilizer after they are well established. Too much fertilizer stimulates wood and leaf growth rather than fruit production. Fertilize seldom and sparingly after the first two years.
Fruit thinning is not generally practiced with grapes.
Germination Time (Days)
Not typically planted from seed
Seed Germination and Temperature Range
Not typically planted from seed
Common Fertilizer Deficiencies
Iron deficiency, or chlorosis is common in overwatered grapes. This is especially a problem with concord grapes, the most widely grown juice grape in the Western United States. Chlorosis is characterized by pale, small, yellowed leaves with dark green veins. In very severe cases, the edges of the leaves dry up and turn brown, and vines grow and yield poorly.
If your grapes show signs of chlorosis, the first remedy is to reduce the frequency of watering, If the condition persists, apply Iron Sul or use Sequestrene 138 at about 1 pound per 100 feet of row to the soil. The Sequestrene 138 treatment will generally last for about two years. Grapes do not respond well to foliar sprays of iron.