Florida’s warm, humid climate supports beautiful year-round greenery but it also creates conditions where tree diseases can spread quickly. Understanding which issues appear seasonally helps homeowners protect their landscape, prevent long-term damage, and maintain healthy, thriving trees.

From spring fungi to summer stress and winter infections, here are the most common tree diseases found throughout the Southeast and what you should look for right here in the Tampa Bay area.

🌸 Spring Tree Diseases

Spring brings new growth but also increased moisture, making it the peak season for fungal infections.

Brown Blossom Blight

This disease affects flowers, leaves, and young twigs, causing browning and dieback. Planting disease-resistant species and pruning early in the season helps reduce risk.

Anthracnose

A very common spring fungus in Tampa, anthracnose leads to leaf spots, premature leaf drop, and twig dieback. While often more cosmetic than harmful, removing fallen leaves helps prevent recurrence.

Oak Leaf Blister

Seen frequently on Florida oaks, this fungus creates raised, blister-like bumps on leaves. Severe infections may lead to early leaf drop. Good sanitation, removing infected leaves,helps prevent spreading.

Oak Wilt (Serious)

Oak wilt is one of the most dangerous tree diseases in the Southeast. It spreads quickly, especially in red oaks, causing wilting, discoloration, and rapid decline. Preventative fungicide injections can help protect vulnerable species during the growing season.

Apple Scab

Affecting ornamental crabapples common in landscaping, this disease causes scab-like lesions and eventual leaf thinning. Fungicidal treatments in early spring are typically effective.

☀️ Summer Tree Diseases

Tampa’s hot, humid summers create ideal conditions for disease-producing fungi, nutrient issues, and pest-related infections.

Chlorosis

When trees can’t produce enough chlorophyll, leaves turn yellow while veins stay green. Poor soil structure, nutrient deficiencies, or high pH can cause it. Soil testing and proper fertilization help reverse the condition.

Powdery Mildew

This fungus coats leaves in a white, powdery film and stunts growth, especially in shaded or overcrowded areas. Simply improving sunlight exposure and airflow can make a big difference.

Lethal Yellowing (Palms)

A major concern in Florida, lethal yellowing affects palms like coconut, areca, and date palms. Early signs include premature fruit drop and yellowing fronds. Insect management and timely antibiotic injections can save affected palms if caught early.

🍂 Fall Tree Diseases

As temperatures cool and humidity stays high, several root and cone diseases become more noticeable.

Heterobasidion Root Disease

A serious root-rot fungus that forms conks at the base of stressed or weakened trees. Because the fungus often hides under leaf litter, regular inspections are important in the fall.

Southern Cone Rust

Affects oak species common in Tampa. Spores spread during pollination and cause visible deformities on new conelets.

Hispidus Canker Decay

Creates large, elongated cankers and produces dark, mushroom-like growths. Unfortunately, there is no cure, but proper pruning, fertilization, and watering can slow progression and support surrounding trees.

❄️ Winter Tree Diseases

Even during Florida’s mild winters, some infections remain active.

Black Knot

A fungal disease causing black, swollen growths on cherries and plums. Winter is the best time to prune infected branches before new growth emerges.

Annosus Root Rot

A dangerous disease that affects pines and other evergreen species. Look for reduced vigor, crown thinning, or fungal growth around the root zone.

🌳 Common Questions About Tree Disease

How can I tell if my tree is diseased?

Early signs include:

• Premature leaf drop
  
  
• Discolored or spotted leaves
  
  
• Visible fungi or conks
  
  
• Bark wounds without an obvious cause
  
  
• Unusual wilting or branch dieback
  
  

If something looks “off,” it’s worth getting checked.  Many diseases spread quickly in Florida’s climate.

Is it bad to have a diseased tree?

Yes. Even mild diseases weaken tree structure. Severe ones can lead to falling limbs, root failure, or the complete loss of the tree.

What should I do if I suspect a disease?

Avoid cutting or trimming the tree yourself, as it can worsen the issue or spread spores.

Instead, call a certified arborist for a proper diagnosis and action plan.

🌴 Keep Your Tampa Trees Healthy All Year

Seasonal tree diseases can cause serious long-term damage if left untreated. Regular inspections, selective pruning, and proper maintenance help keep your property safe and your landscape thriving.

For a professional evaluation and proven treatment solutions in the Tampa Bay area, call Toby at Signature Tree & Home: (813) 516-4459.

Your trees and your home deserve year-round protection.