Red Alder
Alnus rubra
Pioneer species found throughout the Tri-Cities, especially near creeks and in recovering forest areas. Common along the Traboulay PoCo Trail.
FormbarkbarkHow to recognise it
Height
15-25m (50-80ft)
Trunk
Up to 0.5m diameter with thin, smooth, light grey bark often covered with lichens
Needles
Oval leaves (7-15cm) with doubly-serrated edges and pointed tips, edges slightly rolled under
Cones
Small woody cones (1-2cm) that persist on the tree year-round
Quick check
- Smooth, pale grey bark with white patches
- Leaves with rolled-under edges
- Persistent small woody cones
- Inner bark turns orange when scratched
- Often grows in dense stands
Photo guide
5 things to look for: photographs coming
Care
Watering. Prefers moist conditions, naturally found near streams. Relatively drought-tolerant once established.
Pruning. Generally not pruned as an ornamental. Remove hazardous deadwood as needed. Best time: Late fall to winter when dormant
Maintenance. Low maintenance but short-lived. Plan for replacement as trees age. Nitrogen-fixing roots benefit nearby plants.
Common issues
- Short-lived (40-60 years typical lifespan)
- Tent caterpillars
- Alder flea beetle
- Phytophthora root rot in wet conditions
Roots
Shallow, spreading root system with nitrogen-fixing nodules Moderate spread, typically matching canopy width
Hazards
Windfall risk
High
Branch drop risk
Medium
Warning signs to watch for
- Bracket fungi on trunk
- Significant lean
- Sparse foliage in crown
- Bark falling off in patches
- Multiple dead branches
Removal considerations
Difficulty: LowTypical cost: $$- Relatively soft wood, easy to cut
- Often grows in clusters requiring multiple tree removal
- Smaller size makes access easier
- Wood decays quickly if left on site
- Often protected near streams and wetlands
Permits
Permit thresholds vary across the region: 15cm or 5m tall in Port Coquitlam, 20cm in Anmore, Coquitlam, Maple Ridge, Pitt Meadows, New Westminster and Delta, 30cm in Port Moody and Surrey, and 30.5cm for conifers in Burnaby (Belcarra regulates only trees 5m+ in its mapped permit areas). Alder is treated more leniently than most - Maple Ridge excludes it from the 'significant tree' category that triggers heavier replacement, and Port Coquitlam excludes cottonwood and aspen the same way. The basic permit threshold still applies, and riparian setbacks still override everything.
Tree bylaws by city