Tree Service in Pasadena, California

Pasadena's tree ordinance (PMC Chapter 8.52) protects three categories of trees.

Street trees: All trees in the public right-of-way are City property. Any trimming, removal, or alteration without written City authorization is a violation — even well-intentioned pruning by a homeowner.

Protected private trees: On private lots, coast live oak, valley oak, California sycamore, and California black walnut are protected regardless of size. Any tree of any species with a trunk diameter of 8 inches or more at breast height also requires a permit for removal.

Heritage trees: The City maintains a Heritage Tree Register of individually significant trees. These carry their own enhanced permit requirements.

Penalties for violations are serious. Unpermitted removal of a protected tree can result in fines up to $25,000 per tree. The City may also require mandatory replacement planting — often at a 3:1 ratio or higher for large specimens. You can also face civil liability for the appraised value of the tree.

The bottom line: before removing any tree in Pasadena, verify its protected status with an ISA Certified Arborist first.

The process typically takes 4–8 weeks. Here are the steps.

Step 1: Find out if your tree needs a permit. Protected species (oak, sycamore, walnut) always require one. Any tree 8 inches DBH or larger also requires a permit. An ISA Certified Arborist can confirm this during a site visit.

Step 2: Get an arborist report. Pasadena requires a written report from an ISA Certified Arborist. It must document the tree's species, size, health, and structural condition — and clearly state the reason for removal. The arborist's ISA credential number must appear on the report.

Step 3: Submit your permit application to the Planning Department. The City may visit the site before making a decision. For large heritage trees or historic overlay zones, a public notice period may apply.

Step 4: Wait for the City's decision. The City arborist will approve, conditionally approve, or deny the application. Healthy, structurally sound trees are commonly denied — the City's default position is preservation.

Step 5: Meet any conditions before scheduling removal. This may include replacement planting, bond posting, or protective fencing during construction.

We manage this entire process for Pasadena clients — from the first consultation through permit approval.

These are two very different conditions. Distinguishing between them matters because the right response is completely different.

California Oak Moth (Phryganidia californica): Oak moth larvae feed on coast live oak foliage in spring. You'll see progressive leaf loss — starting at branch tips — along with small greenish-tan caterpillars on leaf surfaces or hanging from silk threads. Defoliation can be dramatic and make the tree look dead. But coast live oaks are resilient. Most trees fully refoliate within 4–8 weeks. A single defoliation event is rarely permanently damaging. The usual response is monitoring, not treatment.

Sudden Oak Death (SOD) — Phytophthora ramorum: SOD is a water mold pathogen linked to widespread oak mortality in Northern California. Its presence in the Pasadena area is far less established, but it is worth knowing the signs. Symptoms include dark, wet-looking stains on the lower trunk bark — sometimes with a foul odor — followed by foliage browning that moves from the outer canopy inward. Unlike oak moth defoliation, SOD symptoms do not reverse. However, several other conditions can look similar. Accurate diagnosis requires a laboratory tissue sample — not a visual assessment alone.

If you see bleeding cankers on a Pasadena oak, contact an ISA Certified Arborist for a formal assessment before drawing any conclusions.

Often yes — and many Pasadena property owners don't find out until they're already mid-permit.

Pasadena's Planning Department reviews all building applications for proximity to protected trees. If your proposed construction — including the ADU footprint, foundation, utility trenching, or retaining walls — falls within 50 feet of a protected tree's trunk (or within its critical root zone, whichever is greater), the plan checker will typically require an arborist report before issuing the permit.

This is more common than it sounds. Pasadena's backyard ADU boom has led to many permit surprises. Property owners discover mid-application that an oak or large protected tree requires arborist documentation they hadn't planned for. The practical consequence is project delay — arborist report preparation and City review can add 4–8 weeks to your timeline.

The best approach: bring in an ISA Certified Arborist at the very start of your design process — before plans are drafted. A good arborist will identify all protected trees, map their root zones, and advise your architect on where to position the footprint and utilities to avoid triggering the full report requirement. Catching it early almost always costs less than redesigning plans after the permit application is already submitted.