Annabelle Hydrangea
Hydrangea arborescens 'Annabelle'
Height
120–150 cm
Flower size
20–25 cm (ball)
Bloom time
June – September
Light
Partial Shade / Full Shade
Watering
Very Abundant
Hardiness
Zone 3 (up to -40°C)
Fragrance
None
Advantages and Disadvantages
Advantages
- Unique ability to bloom abundantly in shade where others won't grow
- Giant spherical flower heads (up to 25 cm)
- Absolute hardiness (roots don't freeze even in severe winters)
- Very easy to propagate by cuttings or division
Disadvantages
- Thin shoots often flop under the weight of wet flowers (requires support)
- Foliage may yellow in alkaline soils (chlorosis)
- White color is short-lived (turns green quickly by autumn)
Use in Landscape Design
The queen of the shady garden. Perfect for dense hedges along fences or north walls. In mixed borders, it's a great backdrop for hostas, astilbes, and ferns. Creates a 'white garden' effect at twilight.
Variety Description: White Spheres
An old American variety of smooth hydrangea. Hemispherical bush with large bright green leaves. Starts lime-green, turns pure white, then back to pistachio green by late summer. Very fast grower, reaching max size by year 3.
Planting and Shade
Unlike roses, Annabelle dislikes scorching sun. Leaves will burn and flowers will shrink. Ideal: morning/evening sun only. Soil: loose, moisture-retentive, slightly acidic. Surface root system — don't plant near aggressive trees like Birch or Spruce.
Watering (Crucial)
Water consumption champion. If you miss a watering in heat, leaves will wilt like rags. Use rainwater or soft water. Mulching is mandatory!
Pruning: The Secret to Strong Stems
Main issue is thin branches. 1. Hard Pruning: In early spring or late autumn, cut ALL shoots to 10–15 cm (2 buds). This stimulates powerful new shoots that hold heads better. 2. Light Pruning: Results in a taller bush with more, but smaller, floppier flowers.
Winter Preparation
Indestructible. Even if shoots freeze above the snowline, it recovers and blooms same year (current year growth). No cover needed. Cut flower heads in autumn to prevent snow damage.
Diseases: Chlorosis
If leaves turn pale yellow with green veins, it's chlorosis (iron deficiency). Acidify the soil and use chelated iron sprays.