By: Shelby McCullough| Published: September 19, 2026
TL;DR: A tree can look green and healthy while hiding serious structural defects inside its trunk, branches, or roots. Knowing the seven key warning signs — from fungal conks to a sudden lean — lets Central Florida homeowners act before the next storm does. When in doubt, an ISA-Certified Arborist assessment is the safest and most reliable next step.
Florida’s trees are assets — they provide shade, curb appeal, and real estate value. But a hazardous tree is a liability, and the warning signs are often hiding in plain sight.
The hard truth: a tree can remain green and appear healthy while having serious structural problems in its trunk, branches, or root system. Catching defects before a storm is almost always cheaper — and safer — than dealing with the aftermath.
Below are seven warning signs that a tree on your Central Florida property may need professional attention. Not every sign automatically means the tree must come down, but each one warrants a call to an ISA-Certified Arborist for a proper risk assessment.
1. Large Dead or Hanging Branches (‘Widow Makers’)
Dead limbs — especially large ones — are among the most recognizable hazards in any tree. A dead branch loses the flexibility and structural integrity of healthy wood and can fall without warning, even on a calm day.
Pay close attention to dead limbs positioned above your home, driveway, pool enclosure, vehicles, or any frequently used area. The higher and heavier the branch, the greater the impact risk below.
What to do: Do not attempt to remove large overhead dead limbs yourself. Contact a certified arborist — limb removal at height requires proper equipment and training.
2. Fungal Conks or Mushrooms on the Trunk or at the Base
This is one of the most serious — and most misunderstood — warning signs. Mushrooms or conks (hard, shelf-like fungal growth) on or at the base of a living tree are not just cosmetic. According to the University of Florida IFAS, the presence of conks or other fungal fruiting bodies can indicate significant decay damage inside the tree — often well before the outside looks alarming.
Fungal decay fungi work by breaking down the wood’s structural components — lignin and cellulose — from the inside out. By the time you see fruiting bodies on the exterior, the infection is typically already well established internally. Conks growing near the base of the trunk may specifically signal root rot, which directly threatens the tree’s ability to stay upright.
Clemson Extension forestry researchers note that mushrooms or conks on branches, trunks, or at the base indicate advanced decay and a high probability of tree failure. This is especially critical in Florida, where our warm, humid climate accelerates fungal activity year-round.
What to do: Do not ignore fungal growth on a living tree — and do not fill cavities with foam or concrete, as this does not stop decay. Have an arborist identify the fungal species and assess the extent of internal damage.
3. A Sudden or Increasing Lean
Some trees naturally grow with a slight lean, and that is not automatically cause for alarm. However, a tree that begins to lean quickly, or one that has shifted position after heavy rain or strong winds, needs immediate professional inspection.
According to the UF/IFAS Tree Risk Assessment resource, a tree that starts to lean quickly needs immediate attention, while one that leans slowly over time should still be evaluated by an ISA-Certified Arborist.
A new or worsening lean is often a sign of root failure — particularly dangerous here in Central Florida, where our sandy soils and high water table mean tree roots can be shallower than in other regions. Trees growing in areas with poor drainage or a high water table may have shallower roots and can topple when soils become saturated and high winds are present.
FEMA’s own hazardous-tree guidance identifies trees leaning at an angle greater than 30 degrees as eligible for removal after a disaster — but proactive removal before a storm is always preferable.
What to do: If you notice a new lean or one that seems to be progressing, keep people and vehicles away from the fall zone and call an arborist promptly.
4. Trunk Cracks, Splits, or Seams
A vertical crack running along the trunk — especially one that reaches toward the base or exposes the interior wood — is one of the clearest structural red flags an arborist looks for. Cracks can result from decay, lightning strikes, or the natural stress of a tree with co-dominant stems (two or more main trunks of similar size originating from the same point).
Not every crack means removal is necessary. Some are surface-level, while others compromise the tree’s structural integrity. Telling the difference requires a trained eye and, in some cases, specialized diagnostic tools.
Co-dominant stems — especially those with included bark wedged between them — are particularly prone to splitting. FEMA’s post-disaster criteria specifically flag trees with a split trunk as hazardous and eligible for emergency removal funding.
What to do: Photograph any visible cracks or splits and note whether they appear to be growing. Share that information when you schedule your arborist assessment.
5. Significant Trunk Cavities or Hollow Sections
A cavity — a sunken or hollow section in the trunk or major limbs — forms where decay has eaten away the internal wood, usually starting at an old wound site. The tree may continue growing around the cavity, but the structural strength of that section is reduced.
A useful rule of thumb: a basal cavity larger than about 30% of the stem diameter is a structural concern that warrants professional evaluation. Cavities higher on the trunk deserve the same attention, particularly when combined with other defects like cracks or fungal growth.
A hollow-sounding thud when you tap the trunk with a mallet or your knuckle can be a quick field indicator of internal decay — though a visual check alone does not reveal the full picture. Internal decay, root-plate failure, and advanced disease are not always visible from the outside.
What to do: Do not fill tree cavities with foam, concrete, or any material — this is an outdated practice that does not halt decay or restore strength. Have an ISA-Certified Arborist assess the extent of internal damage.
6. Crown Dieback — Dying or Thinning Canopy
Dieback typically starts at the top of the tree and works its way down toward the base. If more than 25% of the crown is dead or thinning significantly, the tree is in serious decline — a threshold cited by certified arborists familiar with ISA risk assessment methodology.
Crown dieback in Central Florida trees is commonly caused by root damage, soil compaction, prolonged drought stress, pest infestations (such as wood borers), or disease. The tricky part: by the time the canopy shows obvious decline, the underlying problem has usually been progressing for months or years.
Dieback is also visible from the ground in other ways: sparse foliage during the growing season, off-season leaf drop, dead twigs throughout the canopy, or leaves that are unusually small and yellow. A tree in significant decline may be past the point of effective treatment.
What to do: A professional tree health assessment can identify the cause. If the decline is advanced, removal — rather than treatment — may be the safest and most cost-effective path. See our guide on how much tree removal costs in Orlando so you can plan ahead.
7. Exposed, Heaving, or Damaged Roots
Root problems are easy to overlook because roots are mostly hidden beneath soil and mulch — but they are the foundation of every tree’s stability. Several visible clues at or near the base of the tree point to serious root issues:
- Soil heaving or cracking near the base after a storm — a sign the root plate may be lifting
- Mushrooms or conks growing around the base in the soil, suggesting root decay
- Visibly broken or severed root stubs from construction, trenching, or grade changes
- A missing root flare — if the trunk goes straight into the ground like a telephone pole, the tree may have been planted too deep or had soil added over its critical root zone
- Girdling roots — roots that grow in a circle tightly around the base, slowly strangling the tree’s vascular system
According to UF/IFAS, most trees should have a well-defined root flare visible above ground. Visible cavities or swelling in the root collar, fungal conks or mushrooms growing around the base of the tree, or visibly broken root stubs are all clues that root issues may be present.
FEMA’s hazardous-tree standards note that trees with 50% or more of the root ball exposed are candidates for full removal — a clear indicator of how seriously root instability is taken at the highest levels of disaster management.
What to do: Root damage is difficult to assess without professional tools. If you see any of the clues above, schedule an arborist evaluation before the next heavy rain or storm.
The Florida Factor: Why Hazardous Trees Are Especially Dangerous Here
Central Florida’s combination of sandy soils, a high water table, and a June–November hurricane season creates a unique risk environment. Trees with any of the seven defects above are exponentially more likely to fail during a storm — and storm season does not give you time to call for help once winds arrive.
Florida’s legal landscape adds another layer of urgency. Under current Florida law, if a neighbor can prove you knew about a hazardous tree and failed to act, you may bear liability for damage it causes — even across property lines. Proactive removal or documented arborist assessments protect you legally and financially.
If a storm has already damaged a tree on your property, read our guide on what to do after storm damage to your trees in Orlando for immediate next steps.
And if you are unsure whether a permit is required before removing a hazardous tree, check our resource on tree removal permits in Orange and Seminole County — requirements vary by municipality and tree species.
What to Do If You Spot a Warning Sign
- Document it. Take photos of dead branches, cracks, fungi, or soil heaving. Note when the change first appeared and whether it appears to be worsening.
- Stay clear. Keep people, pets, and vehicles out of the potential fall zone until the tree has been assessed.
- Call an ISA-Certified Arborist — not a general landscaper. Tree risk assessment is a specialized skill that requires specific training and credentials.
- Get a written evaluation. A dated written record of your arborist’s findings demonstrates you acted as a responsible property owner — valuable both for insurance claims and liability protection.
McCullough Tree Service has three ISA-Certified Arborists on staff and has served Orange County, Seminole County, and the greater Orlando area for over 30 years. We offer free estimates, financing, and — when a tree truly needs to come down — crane-assisted removal for large or tightly placed trees. Call us before the next storm gives you no choice.
Recommended Reads
- How Much Does Tree Removal Cost in Orlando? (2025 Price Guide)
- What to Do After a Storm Damages Your Trees in Orlando
- Do You Need a Permit to Remove a Tree in Orange or Seminole County?
Sources
- gardeningsolutions.ifas.ufl.edu
- blogs.clemson.edu
- portal.floridadisaster.org
- blogs.ifas.ufl.edu
- texaslawhelp.org
- delkmanagement.com
