Tree & Shrub Disease

Common Tree & Shrub Diseases

Black Knot

• Affects: Cherry trees and purple-leaf plums
  
  
• Active: Spring through summer
  
  Black knot causes dark, swollen growths on branches that can strangle new growth and hinder fruit production. If left untreated, it can cause long-term damage and even kill the tree. Pruning and proper sanitation are key to controlling this disease.
  
  

Black Spot of Roses

• Affects: Roses
  
  
• Active: Spring through fall
  
  Black spot is the most common and serious disease for roses, causing yellowing of leaves, black spots, and defoliation. While it doesn’t kill the plant outright, it weakens it over time and makes it vulnerable to other stresses.
  
  

Boxwood Blight

• Affects: Boxwoods
  
  
• Active: Spring through summer
  
  This fungal disease causes brown leaf spots and dieback, leading to the death of boxwood plants if untreated. Since its discovery in 2011, boxwood blight has spread to several states, requiring prompt professional care to prevent the disease from spreading.
  
  

Cankers

• Affects: Evergreens, hardwoods, and fruit trees
  
  
• Active: Year-round
  
  Cankers are areas of dead or damaged bark caused by fungal infections or insect damage. They can spread quickly and severely affect the health of a tree, leading to branch dieback or even tree death if not managed properly.
  
  

Dogwood Anthracnose

• Affects: Dogwoods
  
  
• Active: Spring through summer
  
  Dogwood anthracnose is a fungal infection that causes tan spots on leaves, which turn into large blotches. The infection can spread to twigs and branches, leading to the potential death of the plant, especially in shaded areas.
  
  

Fire Blight

• Affects: Crabapple, quince, and pyracantha
  
  
• Active: Spring
  
  This bacterial disease attacks flowers, shoots, and branches, causing them to appear burnt. Fire blight spreads quickly via wind, rain, and pruning tools, making immediate action essential to protect your plants.
  
  

Juniper Blight

• Affects: Junipers
  
  
• Active: Spring through summer
  
  Juniper blight causes foliage to turn brown and gray, eventually leading to the formation of cankers. Early detection and treatment are crucial to stopping the spread and saving affected plants.
  
  

Leaf Gall

• Affects: Azaleas, camellias, and hardwood trees
  
  
• Active: Spring
  
  Leaf galls are caused by insect or mite activity, leading to abnormal leaf growth. While they rarely kill the plant, they can weaken it over time. Management involves controlling the insect or mite populations responsible.
  
  

Powdery Mildew

• Affects: Euonymus, crepe myrtles, dogwoods, cucumbers, squash, tomatoes, and more
  
  
• Active: Spring through summer
  
  Powdery mildew gives plants a dusty, white coating and can significantly affect plant health. It spreads through the wind and old plant material, so it’s important to manage the disease early to avoid long-term damage.
  
  

Rose Rosette Virus

• Affects: Roses
  
  
• Active: Spring through summer
  
  This viral disease causes distorted growth and is transmitted by a specific mite. Unfortunately, there is no cure for rose rosette virus, and infected plants should be removed to prevent the spread to healthy roses.
  
  

White Oak Wilt

• Affects: White oaks and other oak species
  
  

Active: Spring through summer

White oak wilt is a deadly disease that affects the vascular system of oak trees, leading to rapid tree decline. It is spread by beetles that carry fungal spores. Immediate attention and management are essential to protect your oaks.

Protect Your Trees and Shrubs with Titan Pest Defense

Proper care, early detection, and effective treatment are critical in managing tree and shrub diseases. If you notice any symptoms of disease in your plants, it’s essential to take action right away. Titan Pest Defense offers professional services to protect your landscape, prevent damage, and ensure your trees and shrubs remain healthy.