Common Disease Problems
Botrytis Bunch Rot: Flattened, black masses of fungus appear on canes. Open flowers can become infected which in turn infect the berries. Berries become mummified. Burpee Recommends: Prune to improve air circulation. Allow fruit to ripen in an open canopy by pruning accordingly. Remove mummified fruit as the disease overwinters in the berries.
Crown Gall: Rough, wart-like growths or galls appear on the crown at or just below the soil surface. These can also form on the stems or canes. Plants can become stunted, subject to drought stress and wind damage. Large enough galls may cause girdling which results in plant death. Burpee Recommends: Examine the canes prior to planting for any indication of galls. Avoid injury of the plant. You can remove the gall if it is small enough by cutting around it into healthy wood allowing that area to dry out, cutting into healthy tissue as little as possible. If plant is severely infected, remove it.
Downy Mildew: This fungus causes whitish gray patches on the undersides and eventually both sides of the leaves and all green parts of the plant. Burpee Recommends: Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet. Contact your Cooperative Extension Service for fungicide recommendations.
Pierce’s Disease: The severity of this disease varies depending on time and length of infection. Leaves become slightly yellow or red along the margins in white and red varieties respectively, eventually causing the margins to dry or die. Fruit clusters will shrivel. Leaves will fall off leaving petioles attached to the stems. New wood will mature irregularly. Burpee Recommends: Remove infected vines during the dormant season. If severely infected, harsh pruning may be required.
Powdery Mildew occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Common Pest and Cultural Problems
Ants: Feed on the fruit. Burpee Recommends: Avoid using cover crops near grape plantings, unless using common vetch, which helps deter ants from eating grapes. Control mealybugs and aphids, which attract ants.
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Discolored Foliage: Brown foliage can result from drought stress, particularly in mid-summer. Burpee Recommends: Water regularly and use mulch to conserve water and control weeds.
Grape Bud Beetle: Light gray beetles open crop buds and eat the centers. Burpee Recommends: Contact your Cooperative Extension Service for control assistance.
Mealybugs: The grape mealybug has two generations each year and overwinters as an egg or as crawlers. They are flat, oval-shaped, white and waxy. They contaminate grape clusters with cottony egg sacs and leave behind black sooty mold. They can transmit grape viruses. Burpee Recommends: Introduce natural enemies to the area such as ladybugs. Contact your Cooperative Extension Service for control assistance.
Do I need two different varieties to get fruit? No, grape plants are self-fruitful and do not need cross pollination by another variety.
Can we make our own wine? Yes, if you are using the right grapes, the right culture to produce a high sugar grape and the right fermenting process.
What can I spray on my grapes? Burpee cannot advise on any chemical application to any plant. Please contact your local Cooperative Extension Service for the best cultural and chemical practices in your area.
What grape variety can I grow in zones 9-10? Native muscadine grapes are best to grow in warmer climates. Always check the zone recommendations when choosing a variety as many grape require cold winters.
Will I get fruit the first year? No. Expect first fruit in 2 years after planting and 3-5 years after planting for full fruit.