Grapes Growing GuideGrapes Growing Guide
- Soil preparation: Prepare your planting site a year before you actually plant vines. Has the soil tested? Double dig the site and add amendments based on the soil test’s recommendations. Grapes grow well at a soil pH between 5.0—6.0.
- Spacing: In a vineyard, most growers space grapes 8 feet apart in rows with eight feet between them; in even the most compact quarters, allow at least 3 feet between vines. Build your trellis before you plant. In mild winter areas—zone 7 and warmer—you can plant bare-root grapevines in late fall or early winter. In colder climes, wait to plant them until early spring. If you plant grafted vines, be sure to keep the graft union above ground level.
- Fertilizing: Overfertilizing causes vines to grow vigorously but produces few fruit. Mulch the vines with compost in late winter each year.
- Special hint: Planting a variety that is resistant to common diseases in your area helps prevent problems. Try ‘Aurore’, ‘Baco Noir’, ‘Bluebell’, Canadice’ (seedless), ‘Carlos’, ‘Concord’, ‘Edelweiss’, ‘Interlaken’ (seedless), muscadine grape, Seyval’, or Steuben’.
A study conducted by Iowa State University showed that although half of all organic vineyards surveyed had grape leafhoppers on their vines, they had minimal impact on the crop. Keep an eye on your crops and be ready to take action if insects become a problem.
When it comes to disease, early intervention is the key. The diseases that afflict grapes differ vastly from one climate to the next. Your best bet is to ask other gardeners, nurserymen, or your local Master Gardener program about the diseases prevalent where you are before you plant.
- Rusty brown leaf spots and hard, blackberries “mummies” signal black rot.
- A fine, white powder on leaves, shoots, and fruit clusters may be downy mildew.
- Powdery mildew appears first as a gray moldy material on canes, then it spreads to leaves and fruit.
As grapes ripen, their final pigments appear—usually red, sometimes blue—and the stems get woody. Taste before you harvest; sugar content changes throughout the day and throughout the harvest season, so wait until grapes are as sweet as you’d like them to be before you pick a cluster.
1. Raintree Nursery, Morton, WA
Sources for supplies
Other Grape Resources:
Here are some resources on managing grape pests and diseases:
The Grape Grower: A Guide to Organic Viticulture, by Lon Rombough
A great guide to growing grapes organically. Contains information on managing common pests and diseases organically, as well as planting, variety selection, and vine maintenance.