Professional Tree Services in Southern California

For most deciduous trees (those that drop leaves), late winter (January to early March) is the “sweet spot.” Pruning during dormancy reduces stress and minimizes sap loss. However, there are local exceptions:
Palms: Best trimmed in late spring or early summer to remove flower stalks before they drop debris.
Oaks: Best pruned in the hottest part of summer or deepest winter to avoid the active season of pests like the Goldspotted Oak Borer.

Often, yes. Many Southern California cities have “Protected Tree Ordinaries.” For example, in Los Angeles, species like Coast Live Oaks, Western Sycamores, and California Black Walnuts are protected. Removing them—or even pruning more than 10% of their canopy—typically requires a permit from the Urban Forestry Division and may require a report from a Certified Arborist.

The “deep watering” technique is essential. Instead of frequent light sprinkles, use a soaker hose or a slow-drip bucket to soak the soil 12–18 inches deep at the “drip line” (the edge of the tree’s canopy). Mature trees usually only need this once a month during dry spells.
Note: Do not water the trunk directly, as this can lead to root rot and fungal diseases.

Southern California is currently facing a major infestation of Invasive Shot Hole Borers. These tiny beetles tunnel into trees and spread a fungus that disrupts the tree’s “plumbing.”
Sign: Perfectly round entry holes (the size of a ballpoint pen tip) often accompanied by “bleeding” sap or white powdery residue (frass).
Action: If you see these, contact an arborist immediately. These pests spread rapidly through moving firewood.

Absolutely. In “Very High Fire Hazard Severity Zones,” insurance companies often require defensible space. This includes:
Removing “ladder fuels” (low-hanging branches that allow fire to climb).
Maintaining a 10-foot clearance between tree canopies and your chimney or roof.
Thinning out dead wood to reduce the “ember bank” during a wind event.

This is often a sign of Bacterial Wetwood or a fungal infection like Phytophthora. In our climate, it can also be a stress response to extreme heat. While not always fatal, it’s a red flag that the tree’s vascular system is compromised. An arborist may recommend soil aeration or specialized trunk injections.

Because of the high liability in CA, you should never hire a “guy with a chainsaw” without verifying:
License: A valid C-61 / D-49 (Tree Service) contractor’s license.
Insurance: Specifically Workers’ Comp (California law is very strict here; if a worker is hurt on your property without it, you could be liable).
ISA Certification: Look for an International Society of Arboriculture (ISA) Certified Arborist to ensure the health of the tree isn’t sacrificed for a quick trim.