Grapevines are lovely climbing plants that can produce generous portions of fruit year after year. Proper care of grapevines requires consistent monitoring for pests and diseases as well as diligent supplementation and observation of the vines' overall environment. Vines also require regular pruning to promote healthy growth and good fruit production. When it comes to grapevines, the best rule of thumb is that an ounce of prevention is truly greater than a pound of cure.
The most common pests for grapevines are grape flea beetles, mites, and leaf hoppers. Grape flea beetles winter on the plants' leaves and feed on newly formed spring buds. Mites live in the dead leaves at the base of the grapevines and wait for summer's fruit to form. Mites can also carry diseases, so it is best to keep them under control with mite predators. Leaf hoppers eat the bottom sides of grape leaves and cause severe foliage damage. Hybrid varieties are the most susceptible to leaf hoppers.
Diseases can infect grapevines rapidly and greatly affect the plant's yield. Crown gall appears at the base of the grapevines and causes large galls that initially appear white and fleshy, but as the plant dies become woody. Mildews effect the flavor of the fruit and cause a white powdery appearance on all green surfaces of the plant. Bacteria, yeasts and fungi can cause the fruit to rot and smell like vinegar. To avoid diseases, treat for pests early and keep the ground as clean and dry as possible.
Grapevines require supplementation of manganese, nitrogen, potassium, magnesium, boron and iron. Vines should be fed fertilizers twice annually, once in the spring as the buds are forming and once in the autumn after the fruit has been harvested. Organic alternatives are available such as molasses for iron and fish fertilizer for magnesium.
Grapes are extremely sensitive to sun, and can be easily sun-burnt if directly exposed to sunlight. To avoid that problem, never prune branches where there is fruit underneath. Birds love feeding on grapes and will completely pick the fruit from the vines; consider using garden netting to prevent birds from ravaging your grapes. Finally, grape branches and leaves are extremely sensitive to late spring freezes and will turn brown if not properly protected.