The first rule for growing grapes is choosing the right location. All grapes like a sunny spot with rich, well-draining soil and good air circulation. Don't crowd the plants. You don't need flat terrain, but if you're growing on a hillside, plant above the lowest-lying spots to help prevent both frost damage and mildew.
Grapes need a strong support system that can handle the heavy fruit. In vineyards, grapes are often grown on horizontal wires between posts, and this system also works well against a fence or along a path. Another good option is a rail fence. Grapes also grow well over an arbor or pergola. Whichever support you choose, put it in place before planting.
Buy and plant bare-root vines when they are dormant, during the winter in mild-winter areas and about three weeks before the last frost in colder areas. The planting holes should be deep enough so the plant will be set at the same depth it was grown at in the nursery (look for the soil mark on the trunk) and wide enough to allow you to spread out the roots.For American and European grapes, space the holes about 8 to 10 feet apart. For muscadine grapes, the holes should be 12 to 15 feet apart. If you're using an arbor or fence as a support, dig each hole about 1 1/2 feet away from the support. If you're planting in rows, space the rows 10 to 12 feet apart for American and European varieties and 20 feet apart for muscadine varieties.
If the roots are dry, soak them for up to four hours before planting. Remove any damaged roots, and trim the remaining ones to approximately 6 inches long. Carefully set the plant in place and spread the roots out. If you're planting against an arbor or fence, lean the plant at a 45-degree angle toward the support. Cover the plant with the soil you removed from the planting hole, and then cut the top growth back to just two or three buds. Water thoroughly.
Keep grapes watered regularly throughout the growing season; they usually need about 1 inch per week. If you don't have rainy summers, drip irrigation or watering basins are ideal; grapes are prone to fungal diseases, which can be exacerbated by overhead watering.
Fertilize in spring, just as the buds swell, using a balanced fertilizer. For just-planted grapes, use only one-quarter the recommended amount. Increase the amount of fertilizer to one-half the recommended amount the second year and three-quarters the recommended amount the third year. From the fourth year on, use the recommended amount.
Grapes can be troubled by a number of pests, including aphids, grape leafhoppers, grape mealy bugs, and grape berry moths. Birds are also attracted to the crop. Fungal diseases, especially mildew, can be a problem, especially for European grapes.
The first line of defense is good gardening practices. Start by keeping the plants well watered and ensuring they have good air circulation. Keep the area weeded, as weeds can harbor damaging insects. Pick up and discard any fallen or diseased leaves. Clean up dropped leaves in the fall. Nets will keep birds from getting the fruit.
Aphids and leafhoppers may be controlled with beneficial insects, strong bursts of water, insecticidal soap, or biological controls. Use horticultural oil spray in late winter on mealy bugs. Control mildew by allowing good air circulation and keeping the leaves dry. Use neem for downy mildew; powdery mildew can be controlled with sulfur dust. For more serious problems, check with your local nursery or agricultural extension agent.
Harvest grapes when the fruit is fully colored and sweet. Cut the bunches of American, American hybrid, and European grapes from the vine. Shake muscadine grapes loose onto a cloth.