Most trees that come down in a storm gave some warning first. A crack that had been there for a year. A limb that went bare and stayed that way. A lean that got a little worse every summer.
You don’t have to be an arborist to spot those clues. Here are the seven we look for first, based on the same checklist University of Florida IFAS Extension teaches homeowners, with notes on how they tend to show up in East Valley yards.
1. Dead or hanging branches
A broken limb stuck up in the canopy is about as obvious as hazards get. Arborists call them hangers, and they can drop on a calm day. Also look for branches with no leaves or missing bark when the rest of the tree is leafed out. Keep in mind that many desert trees shed leaves in drought or cold, so bare twigs alone don’t mean a limb is dead. Scratch a small twig with your fingernail. Green underneath means it’s alive.
2. Cracks in the trunk or big limbs
A vertical split, a seam that opens and closes in the wind, or a crack where a big limb meets the trunk all deserve a closer look. Cracks often show up after monsoon storms, when gusts twist a heavy canopy harder than the wood can handle.
3. Signs of decay
Decay hides inside the tree, but it leaves clues on the outside: shelf-shaped fungus (called conks), mushrooms at the base, soft or crumbly wood, carpenter ants, and holes where birds or animals are nesting. A small pocket of decay can be fine. A trunk that’s mostly hollow is not.
4. Cavities and old wounds
Openings in the trunk usually start with an old injury: a bad pruning cut, a run-in with the mower or string trimmer, a limb that tore off. Trees can wall off damage, but a large cavity means less solid wood holding everything up.
5. Two trunks with a tight “V”
When two stems of about the same size grow from the same spot, they’re called codominant stems. If the angle between them is a narrow V instead of a wide U, bark gets pinched in the joint and it never grows strong. Multi-trunk desert trees like mesquite are prone to this, and it’s one of the most common places trees split in a storm.
6. A new or worsening lean
Lots of trees grow with a lean and are perfectly stable. What matters is change. A lean that appears after a storm, soil heaving or cracking on the opposite side, or roots lifting out of the ground all need attention right away. Shallow-rooted, heavily watered trees are especially likely to tip when monsoon rain soaks the ground and the wind picks up.
7. Root and root flare problems
The base of a tree should flare out where it meets the ground. If it goes straight down into the soil like a telephone pole, the flare may be buried under rock, fill or a raised bed. Also look for roots wrapping around the trunk, swelling or cavities at the base, mushrooms, and roots that were cut for a trench, wall or pool. Root damage can take years to show up in the canopy.
What to do if you spot one of these
A warning sign doesn’t automatically mean the tree has to go. Often the fix is pruning out a dead limb, taking weight off a heavy branch, or changing how the tree is watered. What matters is having someone trained look at it before the next storm instead of after.
In the meantime:
- Keep people, cars and pets out from under any hanging or cracked limbs.
- Take photos so you can tell if a crack or lean is getting worse.
- Don’t climb the tree or cut big limbs yourself, especially anywhere near power lines.
- Have an ISA Certified Arborist take a look. Our post on what happens during a tree consultation explains what to expect.
Get your trees checked
Heartwood’s certified arborists offer tree consultations across Mesa, Tempe, Queen Creek, Gilbert and the rest of our service area. If a tree does need work, we handle tree trimming, tree removal and storm clean up. You can see all of our tree services here. Request a free estimate or call (480) 269-5636.
Related reading: should you save or remove a storm-damaged tree?
Sources
- University of Florida IFAS Extension, Gardening Solutions, Tree Risk Assessment
- International Society of Arboriculture, Verify a Credential
