White Pine
Pinus strobus
Overview
Provincial tree of Ontario, historically important timber tree, remains ecologically and culturally significant
White pine forests once dominated Ontario landscape. Highly valued for timber, particularly for ship masts in colonial era
Identification
Leaves
Soft, flexible blue-green needles in bundles of 5 (count the needles to identify). Needles 3-5 inches long, giving tree a soft texture.
Bark
Young bark is smooth and greenish-gray, maturing to deeply furrowed bark with rectangular blocky pattern.
Flowers
Male cones are small and yellow, female cones are pink to purple, appearing in spring.
Fruit
Long, slender cones (4-8 inches) that hang from branches. Important food source for wildlife.
🦆 Valuable wildlife food source
Growing Conditions
Climate
Excellent adaptation to Eastern Ontario climate, native to the region
Hardiness Zones: 3, 4a, 4b, 5a, 5b
Light Requirements
Soil
Moisture: moist
Drainage: well-drained
pH Range: 4.5 - 7
Tolerance
Care & Maintenance
Pruning
Best Season: December-March
Frequency: Minimal pruning needed
- Prune in December-March when dormant
- Remove only dead or damaged branches
- Can shear when young for denser growth
Avoid: Spring and summer when pests are active
Watering
Establishment: Regular watering for first 2-3 years
Mature: Drought tolerant once established
Seasonal Care Timeline
Spring
- White pine weevil active
- Monitor for blister rust
- Pollen can be abundant
Summer
- Watch for pest activity
- Young trees may need water during drought
- Monitor for disease symptoms
Fall
- Cone drop
- Assess tree health
- Good time for planting
Winter
- Heavy snow can damage branches
- Salt spray damage from roads
- Attractive evergreen in winter landscape
Common Issues
White Pine Blister Rust
HighFungal disease requiring alternate host (Ribes species)
Symptoms: Orange blisters on bark, Branch dieback, Resin flow, Cankers
Treatment: Prune infected branches well below cankers
Prevention: Remove currant and gooseberry bushes within 300m, plant resistant cultivars
Professional arborist recommended
White Pine Weevil
ModerateBeetle that kills terminal leader
Symptoms: Dead or drooping leader, Curved main stem, Multiple leaders
Treatment: Prune out infested leader, train new leader
Prevention: Plant in partial shade, insecticide treatments
Quick Facts
When to Call an Arborist
Recommended inspection: Annual inspection recommended
- •Orange blisters or cankers on branches
- •Dead or dying leader
- •Significant needle loss
- •Structural defects
- •Storm damage
Free consultation for Belleville residents
Recommended Services
Based on White Pine characteristics