• The mountain laurel is one type of shrub found in Georgia.mountain laurel image by Tijara Images from Fotolia.com
  
  The hot, humid environment in Georgia presents many challenges to landscapers in this state. Many people use shrubs to make their yards more aesthetically pleasing. Shrubs are woody plants that are shorter than trees. There are many disease-causing organisms, such as fungi and bacteria, that thrive in this humid atmosphere and infect shrubs with a variety of diseases.
  
  

Root Rot

• Root rot affects all types of shrubs native to Georgia. This disease is prevalent in areas where wet soil has limited drainage. Such areas stay wet, due to overwatering or their position near air conditioning units, hills or gutters. Plants with this condition have roots that are usually mushy, brown and decayed. The rot eventually spreads to the entire plant. Soil-borne fungi are the most common pathogen for spreading this disease. Symptoms of root rot include poor growth, off-color leaves and wilting.
  
  

Powdery Mildew

• This infection can develop when an invading fungus absorbs the plant's nutrients. A whitish, fungal growth found on the leaves of shrubs is the most distinctive symptom. Powdery mildew flourishes in areas of high humidity and is most commonly found in woody plants.
  
  

Leaf Rust

• The rupturing of raised pustules on the underside of leaves creates orange or rust-colored spores. There are usually light-colored or yellow spots on the tops of the leaves where these pustules develop.
  
  

Botrytis Blight

• A fungus causes this condition, which is especially threatening to ornamental plants, like shrubs. Symptoms include spots on leaves, cankers on branches, wilting and the discoloration or death of flowers. Fuzzy, grayish-brown spores spread this disease by wind, and they usually infect other shrubs under humid, cloudy conditions. This disease can rapidly spread from the infected areas of the plant to healthy regions.
  
  

Leaf Spots

• In some cases, bacterial infections cause leaf spots on a variety of shrub types. Leaf spots are typically yellow, angular spots that develop along leaf margins or veins. Because these bacterial pathogens enter plant tissue through water, this condition is most likely to occur in cool, wet conditions.
  
  

Fire Blight

• A bacterial infection causes this widespread, highly infectious disease that can destroy shrubs. Young twigs and branches begin to die and take on a deep rust color. Dead leaves and fruit usually remain attached to branches. Fire blight occurs in wet, warm conditions and is most noticeable from April to June.