Blizzard Mockorange

Philadelphus lewisii ‘Blizzard’

Blizzard Mockorange is a cold-hardy, deciduous flowering shrub known for its abundant clusters of fragrant white flowers in early summer. Developed in Canada, this exceptionally winter-hardy variety thrives in Zone 2-7, making it perfect for hedges, borders, and foundation plantings in Southwest Saskatchewan. With minimal care requirements, drought tolerance, and a strong citrus-like fragrance, it’s an excellent choice for adding beauty and scent to landscapes.

Planting & Location

• Hardiness Zone: 2-7 (one of the most winter-hardy mockoranges, ideal for prairie climates)
• Mature Size: 5-6 feet tall, 4-5 feet wide
• Growth Rate: Moderate (12-18 inches per year)
• Sunlight Needs: Full sun to partial shade (best flowering occurs with 6+ hours of direct sun)
• Soil Preference:
  • Prefers well-drained, loamy soil.
  • Tolerates clay, sandy, and slightly alkaline soils.
  • Avoid overly wet or waterlogged conditions, as it dislikes excessive moisture.
• Spacing: 4-5 feet apart for hedging, 6+ feet apart for individual shrubs.

Watering

• Young Plants (First Year): Water deeply 1-2 times per week to establish roots.
• Established Shrubs: Drought-tolerant but benefits from deep watering every 7-10 days in dry conditions.
• Avoid Overwatering: Prefers moderate soil moisture but does not tolerate standing water.

Fertilizing

• First Year: No fertilizer needed—focus on root establishment.
• Mature Shrubs:
  • Apply a balanced slow-release fertilizer (e.g., 10-10-10) in early spring to encourage strong flowering.
  • Organic alternative: Compost or well-rotted manure in spring.

Pruning & Maintenance

• Best Time to Prune: Right after flowering (mid to late summer) to encourage new growth and blooms for the next season.
• How to Prune:
  • Remove dead, damaged, or weak branches to promote healthy growth.
  • Trim lightly after flowering to maintain shape and encourage fresh blooms.
  • Rejuvenate older plants by cutting back one-third of the oldest stems to ground level every 3-4 years.

Flowers, Foliage & Seasonal Interest

• Bloom Time: Late spring to early summer (June-July)
• Flower Color: Pure white, four-petaled blossoms with a strong citrus fragrance
• Fragrance: Intensely sweet, citrus-like scent
• Foliage:
  • Spring & Summer: Medium to dark green leaves
  • Fall: Yellowish-green before dropping

Pest & Disease Management

Resistant to: Drought, deer, urban pollution, and most pests

Common Pests:

• Aphids – Can cause curled leaves and sticky honeydew.
  • Solution: Spray with insecticidal soap or introduce ladybugs.
• Scale Insects – Appear as small bumps on stems and leaves.
  • Solution: Use horticultural oil in early spring.

Common Diseases:

• Leaf Spot (Fungal or Bacterial) – Causes brown spots on foliage.
  • Solution: Improve airflow and avoid overhead watering.
• Powdery Mildew – White fungal coating on leaves in humid conditions.
  • Solution: Prune to improve airflow and apply fungicide if needed.

Winter Protection

• Extremely winter-hardy—no special protection needed in Zone 2-7.
• Mulching: Apply 2-4 inches of mulch around the base (not touching the stems) to insulate roots.
• Rodent & Deer Protection: Generally resistant to deer, but rabbits may nibble young stems in winter.

Landscape Uses

Great for specimen plantings, hedges, and foundation plantings
Produces intensely fragrant, showy white flowers
Low-maintenance and easy to grow
Attracts pollinators such as bees and butterflies
Works well in cottage gardens, mixed borders, and urban landscapes

Additional Notes:

• Blizzard Mockorange is one of the best flowering shrubs for cold climates, offering lush white blooms, a strong fragrance, and easy-care maintenance.
• Lifespan: 20+ years with proper care.
• Works well in traditional, cottage-style, or prairie gardens.

Photo courtesy of Jeffries Nursery