February 21, 2003
Crown gall is a common disease caused by a bacterium called Agrobacterium tumefaciens. Infected plants are recognized by galls (tumor-like growths) that can be as large as several inches across. They typically form near the soil line, hence the name crown gall. However, they also may form on stems, branches, or under the ground. Rose, euonymus, poplar, apple, and cherry are a few plants that frequently become infected, but just about every other nongrass species is at risk.
Almost any substance can be harmful to human health if used improperly. For example, water is essential to our existence, but one can drown in the liquid form, slip and fall on the solid or frozen form, or be scalded by the gaseous form (steam). Plants are as essential as water because they provide for basic human needs such as food, clothing, shelter, and even the air we breathe. And like water, plants also can be hazardous if used improperly.
When selecting shrubs for the home landscape, our choices are often based on their ornamental characteristics, such as flowers, fruit, or fall foliage. Unfortunately, their mature size is sometimes overlooked. Disregarding plant size often creates problems, such as shrubs blocking windows or interfering with pedestrian traffic. Poorly selected plants also require greater maintenance.