Grapevines, also known as vitis vinifera, are susceptible to a number of diseases.  The most prominent affliction in North America is Pierce’s Disease, which is carried by leaf-hopping insects called sharpshooters. In the United States , the disease is most prevalent in the South, particularly California and the southeast. Any location above the central latitude of the U.S. seems to avoid the disease altogether, especially where cold winter temperatures are present.

Symptoms of Pierce’s Disease include a reddening of the branch, leaf and grape.  Entire vineyards can be wiped out by the disease, which would necessitate destruction of infected vines and replanting.

Black Rot is another prevalent disease, present in the northeast U.S. and Canada .  The disease propagates in warm, humid weather.  Black Rot first appears as yellowish dots on the leaves, with small black dots throughout the yellow spots.  Eventually, the lesions grow, and become reddish-brown, and measure up to a quarter inch in width. Those lesions are fungal centers, which house many spores which spread to other vines. The end result is shriveled grapes, or worse, destruction of the infected vines.  Black Rot can also appear in the shoots and stems of diseased vines.

In areas where vine diseases are common, a good fungicide spray program is essential. In these regions, it’s advisable to plant grapevines in open areas that will benefit from ample sun and air flow.  The main reasoning used in preventing disease is to ensure that the plants can dry as quickly as possible after wet weather. That way, the vines dry out, and the infections don’t have an opportunity to find a home. In addition to the diseases listed here, mildew is also a big destroyer of healthy vines and fruit.

Vineyards can easily be plagued by various animals and insects.  The larger pests, such as deer and birds, are usually easier to keep out, as this is done with fences and bird deterrents. Smaller pests are harder to keep away, and their discovery in any vineyard should be closely monitored.

Phylloxera is a small, green cousin of the aphid that has spoiled many vineyards in North America , and has spread to other locations around the world.  They can possess wings or not, and usually feed on the roots of vines. A result of phylloxera infestation is the appearance of small galls on the vine or leaves.  These galls can cause the deformation of the vine, or cut off the supply of oxygen and water. Fortunately, there are phylloxera-resistant rootstock varieties which have been developed to ward off the vineyard pests.

Beetles, cutworms, red spiders, gophers and rabbits are some of the creatures that can also damage grapevines.  Much skill is required to keep a vineyard pest-free.  Choosing the right rootstock is important, as is determining proper use of fungicide and microclimate management. Ignoring this area of vineyard establishment will likely result in a large loss of time, money and resources.