Leaf Spot Explained

Leaf spot is a common issue seen throughout canopies of the Carolinas. What do these spots mean? Your tree has an infection. Think about how chickenpox shows up in humans. Small bumps appear to let you know a virus is present. A similar thing happens in trees. In the case of Leaf Spot, darkened spots appear to let you know the tree is sick.

Why You Should Care

Leaf spot diseases weaken trees and shrubs by interrupting photosynthesis – the process by which a plant makes its food. Most leaf spot diseases affect only a small percentage of the plant’s overall leaf area and are a minor stress on the health of the plant. However, leaf spot diseases should be taken more seriously if they result in moderate to complete leaf loss 2-3 years in a row. Leaf spot diseases can of be of fungal, bacterial, or viral origin, but fungally-based diseases predominate. 

 

Easy To Spot

Take a look at the leaves on your trees. You’ll want to notice any dark spots present either in a central cluster or in rings. Now, look at the new growth on that same tree. Typically new growth will collapse quickly and have a slimy dark appearance.

 

Signs & Symptoms

  • Leaf spottingdistortion, and/or loss 

  • Pale, off-color foliage 

  • Cankers: dying bark/stem tissue, often circular in shape  

  • Reduced flowering & fruiting 

  • Increased disease susceptibility 

  • Stunted growth & development 

  • Visible spores upon magnification 

 

 

Treatment

Here at Carolina Tree Care we offer both traditional and organic foliar spray treatment options. Since it is the new growth that must be protected and fungi thrive in wet conditions, treatment throughout the early spring vulnerability period is crucial. Sanitation (prompt removal of dead and/or dying plant material) is also vital since it serves as a fungal reservoir to infect new growth. Multiple applications made 7-21 days apart during leaf expansion in the early spring (Mar-Apr) are typical.