Bur Oak

Quercus macrocarpa

Bur Oak is large, long-lived, and an extremely hardy deciduous tree native to North America. It is well-adapted to prairie climates and harsh winters, making it a great choice for Southwest Saskatchewan (Hardiness Zone 3). It is drought-tolerant once established, produces large acorns, and has a majestic, spreading canopy that provides excellent shade.

Planting & Location

• Hardiness Zone: 2-8
• Mature Size: 50-80 feet tall, 40-60 feet wide
• Growth Rate: Slow to moderate (12-24 inches per year)
• Lifespan: 200-300+ years (very long-lived)
• Sunlight Needs: Full sun (minimum 6 hours of direct sunlight)
• Soil Preference:
  • Tolerates a wide range of soils, including clay, loam, sandy, and rocky soils.
  • Prefers well-draining soil, but adapts to moist and dry sites.
  • Highly drought-tolerant once established.
  • Can tolerate alkaline and slightly acidic soil (pH 5.5-8.0).
• Spacing: Plant at least 50 feet apart to accommodate mature canopy spread.

Watering

• Young Trees (First 2-3 Years): Deep water once per week to encourage root development.
• Established Trees: Extremely drought-tolerant; water only during extended dry periods.
• Winter Watering: If fall is dry, provide one last deep watering before freeze-up.

Fertilizing

• First Year: No fertilizer is needed—focus on root establishment.
• Mature Trees:
  • Apply slow-release fertilizer (e.g., 10-10-10) in early spring if growth is slow.
  • Organic alternatives include compost or well-rotted manure applied as mulch.
  • Avoid excessive nitrogen, as it can lead to weak wood growth.

Pruning & Maintenance

• Best Time to Prune: Late winter to early spring (before buds break).
• How to Prune:
  • Remove dead, damaged, or crossing branches to improve structure.
  • Maintain a strong central leader when young.
  • Avoid heavy pruning in summer, as it can attract oak wilt disease (though less common in Canada).
• Acorns: Large acorns drop in fall; may require cleanup if planted near sidewalks or driveways.

Pest & Disease Management

Common Pests:

• Oak Gall Wasps – Cause small, round growths (galls) on leaves and twigs.
  • Solution: Generally harmless, no treatment needed.
• Aphids – Can cause sticky honeydew on leaves.
  • Solution: Encourage natural predators like ladybugs.
• Borers (e.g., Two-lined Chestnut Borer) – Attack stressed trees.
  • Solution: Keep trees healthy with proper watering and mulching.

Common Diseases:

• Anthracnose – Fungal disease causing leaf spots and defoliation in wet springs.
  • Solution: Improve air circulation; rake and remove fallen leaves.
• Oak Wilt (rare in Canada but possible) – A deadly vascular disease.
  • Solution: Avoid pruning in summer when beetles spread the disease.
• Powdery Mildew – White fungal coating on leaves.
  • Solution: Improve air circulation and apply fungicide if necessary.

Winter Protection

• Young Trees: Wrap trunks with tree guards or burlap in winter to prevent sunscald and frost cracks.
• Mulching: Apply 2-4 inches of mulch around the base (keep away from the trunk) to insulate roots from extreme cold.
• Deer & Rodents: Protect young trees from browsing with tree guards or fencing.

Landscape Uses

Majestic shade tree for large yards and parks
Extremely hardy—thrives in harsh prairie conditions
Drought-tolerant once established
Long-lived—provides beauty for generations
Supports wildlife—acorns feed birds, squirrels, and deer
Resistant to strong winds—great for shelterbelts

Additional Notes:

• Bur Oak is one of the best large trees for the Canadian prairies due to its extreme resilience.
• It is a slow grower but worth the wait for its majestic canopy and hardiness.
• Works well in windbreaks, shelterbelts, or as a stand-alone specimen tree.

Photo courtesy of Foothills Nursery