Most trees that fall in St. Louis storms don’t fail because of the storm. They fail because they were already weak.
To spot a storm-weakened tree before it fails, look for six warning signs: a new or worsening lean, cracks in the trunk, dead branches in the upper canopy, fungal growth at the base, hanging or broken limbs stuck in the canopy, and soil lifting around the roots. If you see two or more, get a professional inspection before the next storm rolls through.
Catching these signs early is the single most effective way to protect your home, your family, and your insurance coverage.
Key Takeaways
- Most storm-related tree failures start with pre-existing weakness, not the storm itself.
- Six warning signs cover nearly every storm-weakened tree: lean, trunk cracks, dead limbs, fungal growth, hanging branches, and soil heaving.
- Silver maples, Bradford pears, and ash trees fail most often in the St. Louis metro.
- Trees can look fine for days or weeks after a storm, then fail suddenly in calm weather.
- Homeowners’ insurance may deny claims if a tree was visibly hazardous and ignored.
- A post-storm inspection from a certified arborist costs far less than emergency removal and repairs.
Why Storm-Weakened Trees Are So Dangerous in St. Louis
St. Louis gets hit by severe thunderstorms, straight-line winds, ice events, and the occasional tornado. Each event stresses tree roots, trunks, and branches.
The problem: damage is often invisible from the ground. A tree can survive one storm, look healthy all summer, and come down in a light breeze months later. Arborists call these delayed failures, and they cause a large share of the property damage in the region.
A local St. Louis arborist recently told First Alert 4 that the best way to prevent storm damage is to catch weakness before the tree falls. That is the entire job of a visual inspection.
The 6 Warning Signs of a Storm-Weakened Tree
1. New or Worsening Lean
A sudden lean after a storm is one of the clearest red flags. It usually means the root plate has shifted or roots have torn beneath the soil.
A natural, long-standing lean is usually fine. A new lean, especially one that gets worse over days, is not. Anything past 10 to 15 percent from vertical deserves immediate attention.
2. Cracks or Splits in the Trunk
Vertical cracks, separated bark, or deep splits signal serious structural weakness. Storms expand existing cracks and create new ones that may not be obvious until you walk around the full trunk.
Pay special attention to trees with two main stems growing from the same point. These co-dominant unions split apart under wind load, especially when bark is trapped between them.
3. Dead Branches in the Upper Canopy
Large dead branches high in the tree are sometimes called widowmakers because they can fall without warning, even on calm days.
After a storm, scan the canopy for limbs that have no leaves, brittle bark, or a gray tone that does not match the rest of the tree. These need to come down before they come down on their own.
4. Fungal Growth at the Base or on the Trunk
Mushrooms and shelf-like conks are the visible fruit of decay fungi eating the wood inside. If you see fungal growth at the root flare, on the trunk, or at a major branch junction, the tree is decaying from the inside.
External bark often looks fine while the core is hollow. Tap the trunk with a mallet or heavy stick. A dull, hollow sound confirms internal decay.
5. Hanging or Broken Limbs in the Canopy
After a storm, walk around each tree and look up. Broken branches caught on other limbs are a serious hazard. They can drop suddenly in light wind, during yard work, or when kids are playing below.
Never try to pull these down yourself. They often release in unpredictable directions.
6. Soil Lifting or Heaving Around the Roots
Check the ground around the trunk. If the soil is cracked, raised on one side, or showing exposed roots that were buried before, the tree is losing its anchor.
This is especially common after heavy rain when saturated clay soil loses its grip on root systems. It is often the last warning sign before a whole-tree failure.
Quick 60-Second Inspection Checklist
Walk your property after every major storm and check each mature tree for:
- A lean that looks different than before
- Fresh cracks or split bark on the trunk
- Large dead branches high in the canopy
- Mushrooms, conks, or soft spots at the base
- Hanging limbs caught on other branches
- Raised soil or exposed roots near the trunk
- Partial leaf drop only on one section of the canopy
If you answer yes to two or more, schedule a professional tree risk assessment before the next storm.
Which Trees Fail Most Often in St. Louis
Some species are more vulnerable than others in this region’s soil and weather patterns:
| Species | Common Failure Pattern | Why It Happens |
| Silver maple | Whole-tree or large-limb failure | Weak wood, co-dominant stems, shallow roots |
| Bradford pear | Splits down the middle | Poor branch structure, especially after age 15 |
| Ash | Sudden brittle failure | Emerald ash borer hollows the trunk within 2 to 3 years |
| Pin oak | Branch drop, canopy dieback | Iron chlorosis in local clay soils weakens the structure |
| Sweetgum | Uprooting | Shallow surface roots damaged by construction and compaction |
| Eastern white pine | Whole-tree lean after saturation | Shallow roots in wet, clay-heavy soil |
The Missouri Department of Conservation’s tree care guide covers these species in more detail, including the pests and diseases that make them storm-prone.
What to Do If You Spot a Storm-Weakened Tree
Step 1: Keep Your Distance
Stay out from under any tree showing these warning signs. Keep kids, pets, and vehicles clear of the drop zone until it has been inspected.
Step 2: Document the Damage
Take clear photos from multiple angles, including the base, trunk, and canopy. Date-stamped images support insurance claims and create a record of tree condition over time.
Step 3: Report City-Owned Trees
In the City of St. Louis, trees growing between the sidewalk and curb belong to the city. Use the Forestry Division’s tree problem reporting form rather than hiring a private service for those.
Step 4: Call a Certified Arborist for Your Trees
For trees on your property, hire an ISA Certified Arborist, ideally one with the Tree Risk Assessment Qualification from the International Society of Arboriculture. They will inspect the tree, assign a risk rating, and recommend pruning, cabling, monitoring, or removal based on what they find.
Step 5: Act Quickly on Emergencies
If a tree is leaning toward your home, already cracked, or hanging over a power line, treat it as an emergency. Same-day storm response is available for situations that cannot wait for a scheduled appointment.
How Tree Risk Assessments Affect Insurance and Liability
Homeowners’ policies generally cover sudden, accidental tree damage. Most policies do not cover damage from a tree that was clearly hazardous and ignored.
If a tree falls on your neighbor’s house and your arborist had already flagged it as high risk, your liability exposure goes up. Documented inspections work in your favor. Ignoring warnings works against you.
Frequently Asked Questions
How can I tell if a tree is storm-damaged?
Look for a new lean, fresh trunk cracks, dead or hanging branches, fungal growth, and soil lifting around the base. Two or more of these signs mean the tree needs professional evaluation.
Can a tree fall days or weeks after a storm?
Yes. Delayed failures are common. Wind and saturated soil can damage roots or crack wood in ways that only show up later, often during calm weather or a light breeze.
How soon should I inspect trees after a storm in St. Louis?
Walk your property within 24 to 48 hours after the storm passes, once conditions are safe. Follow up with a professional inspection for any tree showing warning signs.
What does a hanging branch look like?
A hanging branch is broken but still caught in the canopy, resting on other limbs or wedged between branches. It may sway in light wind and can fall without warning.
Are leaning trees always dangerous?
No. A long-standing, gradual lean is usually fine. A new lean, especially one that appeared or worsened after a storm, is a serious hazard.
Can I prune a storm-damaged tree myself?
Small, reachable branches on the ground are usually safe to handle. Anything overhead, anything near power lines, and anything involving a ladder or chainsaw should be left to a professional.
Does homeowners’ insurance cover storm-damaged tree removal?
Most policies cover removal when a tree falls on an insured structure, usually with a cap of $500 to $1,000 per event. General yard cleanup is often not covered. Check your specific policy.
What kind of arborist should I hire for a post-storm inspection?
Hire an ISA Certified Arborist, ideally with the Tree Risk Assessment Qualification. This credential confirms formal training in hazard evaluation.
How much does a post-storm tree inspection cost in St. Louis?
Single-tree inspections typically run $150 to $500. Full-property evaluations with a written report start around $400. Compare that to $1,500 to $5,000 for emergency removal.
Which trees are most likely to fall in a St. Louis storm?
Silver maples, Bradford pears, ash trees (due to emerald ash borer), and pin oaks with chlorosis fail most often in this region.
Can a storm-damaged tree be saved?
Often yes. Selective pruning, cabling, bracing, or weight reduction can stabilize many trees. Removal is the last option, not the first.
What should I do if a tree looks dangerous but hasn’t fallen yet?
Stay clear of it, document it with photos, and call a certified arborist for an inspection within a few days. Do not wait for the next storm to force the decision.
Take Action Before the Next Storm
If you’ve seen even one warning sign, don’t wait for the next storm to confirm it.
Storm-weakened trees rarely get better on their own. They get worse with every wind event, every heavy rain, and every freeze. A single inspection now can save you thousands in property damage and weeks of cleanup later.
Schedule a professional tree inspection with a certified arborist in St Loius today and get a clear answer on whether your tree is safe to leave standing.
