Common Tree Diseases in Florida: Spot the Signs Early

Most tree trouble starts quietly. A yellowing branch in Palm Harbor or a mushroom at the base of an oak in Dunedin can be the first sign of something that will take the whole tree. After Storm Season Prep: Protect Your Trees Before June 1st, this post covers the diseases we see most often.

The Big Three: Most Common Florida Tree Diseases

Ganoderma Butt Rot: Caused by a soil-borne fungus that attacks the lower trunk and roots. Look for:

• Mushrooms or conks (hard, shelf-like growths) at the base of the trunk

• General decline: yellowing leaves, thinning canopy, reduced growth

• Often fatal, there's no cure once the fungus is established

Laurel Wilt: Affects redbay, sassafras, and swampbay trees. Spread by ambrosia beetles. Symptoms:

• Sudden wilting of entire branches or the whole tree

• Leaves turn brown but stay attached

• Dark streaks in the wood when you cut into affected branches

• Usually fatal; infected trees should be removed to prevent spread

Anthracnose: Fungal disease affecting many shade trees (sycamore, oak, maple). Signs:

• Irregular brown or black spots on leaves

• Premature leaf drop

• Twig dieback

• Often cosmetic, but severe cases can weaken trees over time

Other Problems to Watch For

Root Rot (Armillaria, Phytophthora): Common in poorly drained soils:

• Yellowing or wilting leaves despite adequate water

• Mushrooms at the base

• Dark, mushy roots when you dig near the surface

• Often fatal in advanced stages

Leaf Spot Diseases: Various fungi cause brown or black spots on leaves:

• Usually cosmetic and doesn't kill the tree

• Rake and dispose of fallen leaves to reduce reinfection

• Improve air circulation with proper pruning

Bacterial Leaf Scorch: Affects oaks, elms, and other species:

• Leaves develop brown edges that look scorched

• Progresses slowly over months or years

• No cure; tree may live for years but will eventually decline

Is It Really Disease? Common Look-Alikes

Plenty of trees that look sick are really stressed, and stress is far more common than disease in Pinellas and Hillsborough yards. Before you decide a tree has a fungus, rule out the usual suspects:

• Seasonal leaf drop: Many evergreen oaks shed their old leaves in late winter and early spring while new growth pushes out. A yard full of leaves in March can look alarming and is often perfectly normal.

• Drought or too much water: A dry spell, a broken sprinkler head or a downspout that dumps at the base can all cause yellowing and dieback that mimics disease.

• Root damage: A trench for a pool line, a new driveway or a fence post set close to the trunk can injure roots, and the canopy may not show it for a year or two.

• Salt and wind: Trees near the water in places like Clearwater Beach or Madeira Beach can get scorched leaf edges from salt spray and storm winds.

• Lawn equipment: Mower and string trimmer wounds at the base open the bark and let decay in.

A good rule of thumb: stress usually shows up evenly or on the side facing the problem, while disease often moves branch by branch or comes with a visible sign like conks, oozing or dark streaks. If you can name something that changed in the yard in the last two years, start there.

An oak with patches of browning leaves. Decline like this has several possible causes, so have it looked at.

Prevention Is Your Best Defense

Right Tree, Right Place: Plant species suited to your soil, light, and drainage conditions. Stressed trees are more susceptible to disease.

Proper Watering: Water deeply but infrequently. Avoid wetting foliage (promotes fungal growth).

Mulch and Airflow: Mulch retains moisture and regulates temperature, but keep it away from the trunk. Prune to maintain good air circulation through the canopy.

Clean Tools: Disinfect pruning tools between trees (10% bleach solution or rubbing alcohol) to prevent spreading pathogens.

How to Check Your Own Tree in Ten Minutes

You do not need any special tools. Walk the tree on a dry morning and look in the same order every time:

1. The base: Look for mushrooms, conks, soft or crumbling bark, and soil that has heaved or sunk. Check for mulch piled against the trunk.

2. The trunk: Look for cracks, cavities, oozing, or bark that sounds hollow when you tap it.

3. The canopy: Stand back far enough to see the whole crown. Is there a thin or bare section, and is it one side or scattered?

4. The ground under the tree: Look for dropped twigs, dead branches caught in the canopy and fresh sawdust, which can point to borers.

5. The surroundings: Note anything within reach of the tree that would be damaged if it failed, like a roof, a fence, a car or a play area.

Take a few dated photos. A picture from the same spot every month or two tells you far more than memory does, and it helps whoever looks at the tree next.

Who Does What

Here is the honest division of labor. Anthony's Tree and Stump Service cuts, trims and removes trees and grinds or removes the stumps. We are not a plant doctor, and we do not do chemical or injection treatments. For a firm diagnosis, your county's UF/IFAS Extension office is a good place to start, and a licensed applicator handles any treatment that is called for.

Where we come in is the part that is physical and risky: taking out a dead or dying tree safely, trimming back deadwood over a house, and dealing with the stump afterward. If a diagnosis says the tree is not coming back, call us and we will plan the removal around your house, your fence and your neighbors.

One practical note on laurel wilt and other fatal problems: do not haul the wood to another property or use it as firewood somewhere else, because moving infected wood is one way these problems spread. Have the wood chipped or disposed of locally.

When to Call Anthony's Tree and Stump Service

Contact Anthony's Tree and Stump Service if you notice:

• Sudden wilting or decline without obvious cause (drought, construction damage)

• Mushrooms or conks at the tree base

• Dark streaks in wood or oozing sap

• Rapid leaf loss or discoloration affecting large portions of the tree

• Any disease symptoms on a valuable or large tree near structures

Early diagnosis can sometimes save a tree, or at least help you plan for safe removal before it becomes a hazard.

Coming Up Next

Next is Insect Pests Attacking Florida Trees: From Borers to Scale, where we identify the bugs that go after your trees and what to do about them.

Talk to Anthony's Tree and Stump Service

If a tree on your property worries you, call us at (727) 254-0338 or request a free estimate. We serve homeowners and businesses across Pinellas and Hillsborough counties from our Oldsmar office.