How Altadena Handles Landscaping Rules: A Practical Guide

Altadena maintains 68 local ordinances across all categories, and 5 of those deal specifically with landscaping rules. Here is a breakdown of what the city actually requires, what is prohibited, and where Altadena falls on the strict-to-permissive spectrum compared to other cities.

Water Restrictions

Outdoor watering in Altadena (served by Lincoln Avenue Water Co., Las Flores Water Co., Rubio Cañon, and Kinneloa Irrigation District) is limited to 2 days per week assigned by address — typically Mon/Thu odd, Tue/Fri even — with 10-minute-per-zone caps.

Key details: Watering Days: 2/week by address. Odd Address: Mon/Thu. Even Address: Tue/Fri. Hand Watering Cap: 10 min/zone. Authority: SWRCB CCR Title 23 §§996–997.

Each water company sets fines — typically $50 first offense, $100–$500 escalating; chronic violators may have flow restrictors installed.

Grass Height Limits

In Altadena's Very High Fire Hazard Severity Zones, grass and weeds must be kept under 3 inches under LA County Fire Code Title 32 defensible-space rules.

Key details: Max Height in VHFHSZ: 3 inches. Code Section: LA County Fire Code Title 32. Compliance Window: Year-round in VHFHSZ.

Forced abatement plus administrative penalty on tax bill — typically $200–$1,500 cost recovery.

Tree Removal & Heritage Trees

Oak trees (genus Quercus) with a trunk circumference of 25 inches or more (8-inch diameter at 4.5 ft above grade) are protected — removal, damage, or encroachment into the protected zone requires an Oak Tree Permit under LA County Code Chapter 22.174.

Key details: Code Section: LA County Code Ch. 22.174. Protected Size: ≥8 in DBH / 25 in circumference. Protected Zone: 5 ft outside dripline. Replacement: 2:1 typical. Heritage Oak: ≥36 in diameter.

Unpermitted oak removal is a misdemeanor with fines up to $1,000 per tree, plus replacement and restitution. The Altadena CSD also encourages preservation of mature trees.

This is not one of those rules that cities tend to ignore. Altadena actively enforces its tree removal & heritage trees requirements.

Tree Trimming

Trimming protected oak trees (≥8 in DBH) requires an Oak Tree Permit if the work enters the protected zone or removes >25% of crown. Street trees in the public right-of-way are maintained by LA County Public Works.

Key details: Oak Permit Required: Yes if entering protected zone. Code Section: LA County 22.174.040. Parkway Trees: Maintained by LA County DPW. Utility Pruning: Allowed with notice (PUC 911).

Unpermitted oak damage = misdemeanor under 22.174.080 — fines up to $1,000 + replacement value. Damage to public right-of-way trees can result in restitution to the County.

Weed Ordinances

LA County Fire's Brush Clearance program also functions as the weed-abatement ordinance — vacant and improved lots must keep weeds and grasses cut to under 3 inches in fire-hazard areas. Annual notices issued each spring.

Key details: Authority: LA County Fire Code Title 32. Max Grass/Weed Height: 3 inches. Annual Inspection: Spring (notice mailed). Cost Recovery: Property tax assessment.

Non-compliance results in forced clearance (~$200–$1,500 cost depending on lot size) plus an administrative penalty and lien against the property tax bill.

The Bottom Line

Altadena's landscaping rules rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Altadena is broadly strict or permissive.

All of the above reflects Altadena's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.