Santa Ana Winds and Your Trees: A Santa Monica Checklist

Santa Ana season is here. The winds can bring down weak limbs, and the dry air raises fire danger across Los Angeles County. A little work before a wind event cuts the risk to your home, your car and your neighbors.

What Santa Ana Winds Are

The National Weather Service describes Santa Ana winds as dry air flowing from high pressure over the desert Southwest, east to west through the mountain passes of Southern California. They are most common from September through May.

The strongest gusts usually hit the passes, canyons and foothills. The Weather Service notes that Santa Anas often bring little wind to the LA coastal plain, so Santa Monica is not always in the worst of it. Two reasons to prepare anyway: the dry, warm air drives fire danger, and the same weak branches fail in winter storms.

Warning Signs in Your Trees

UC's Integrated Pest Management program lists signs that a tree may be hazardous:

• Trunks that lean or tilt
• Cracks in the trunk or where large limbs meet
• Cavities, cankers or fungal growth
• Dead limbs
• Cracked or lifting soil near the trunk

Two trunks of similar size growing from one point (co-dominant stems) are a common weak spot too, according to UC research on stem failures.

Some problems, like internal decay or bad roots, are hard to see from the ground. If a tree near your house shows any of these signs, have it looked at before the next wind event.

A Wind-Season Checklist

1. Take out dead wood. LA County Fire advises removing dead wood, especially from pine and eucalyptus.
2. Clean up palms. LA County Fire warns that poorly kept palms throw off more embers, which travel farther in wind-driven fires. Remove dead fronds. See palm tree trimming.
3. Give your house room. LA County Fire's defensible space guide says to keep branches at least 5 feet from the house and 10 feet from a chimney.
4. Clear roofs and gutters. The City of Santa Monica lists this among its fire-safety steps.
5. Don't top or over-thin. The city calls topping one of the worst pruning practices and warns against lion's-tailing (stripping a branch's inner growth) too. Both leave a tree weaker. See tree trimming and pruning.
6. Check your fire zone. Some Santa Monica neighborhoods are mapped as Moderate, High or Very High Fire Hazard Severity Zones. The city's fire hazard zone page has an address lookup and the defensible space rules.
7. Street tree looks risky? Trees in the parkway belong to the city, and pruning one needs a permit. Report it through 311 instead. See our Santa Monica tree permit guide.

Trees and Power Lines

Southern California Edison warns that fallen trees and broken branches can bring power lines down.

• Branch caught in a line: report it to SCE at 1-800-611-1911, and don't try to clear it yourself.
• Downed line: SCE says never to touch or approach it. Stay at least 100 feet away, call 911 and tell the operator it's an electrical emergency.

After a Wind Event

• Look up before you walk under a tree. Broken branches can hang in the canopy and fall later.
• Watch for wires. A fallen line can energize a nearby fence.
• Leave big cuts to a pro. University extension guidance warns that bent or pinned limbs can spring back when cut, and that branches over about 6 inches across need experienced hands. See emergency tree service and tree removal.

Who to Call