The “Blue Mist” spirea (Caryopteris x clandonensis “Blue Mist”) provides garden color from midsummer through fall. Also called blue beard and blue spirea, the plant earns its names from the fragrant, purple-blue flower spikes that adorn it for most of the summer season and that attract bees and butterflies. The low-maintenance deciduous shrub grows to only 2 or 3 feet tall and is a suitable addition to borders and flowerbeds. It is hardy in U.S. Department of Agriculture plant hardiness zones 5 through 8 or zones 6 through 9, depending on the source.
Grow “Blue Mist” spirea in well-drained soil where water doesn’t collect after rainfall or irrigation. Provide the plant with a full six to eight hours of sunlight daily. If you grow multiple plants, space them 2 to 3 feet apart in all directions.
Water the shrub only during prolonged dry periods when the soil dries almost completely. “Blue Mist” rarely requires irrigation, and too much soil moisture can kill the plant.
Trim off the plant’s old flower stalks after each flush of blooming, or when they begin to wilt. Cut them back to the top of the shrub. Doing so improves the plant’s appearance and encourages further flowering.
Cut back the shrub in late winter or early spring when its new growth begins. Remove all old, dead stem tips back to the healthy growth, and shape the shrub as desired. Prune the plant to the ground if it dies back completely during winter or to encourage denser new growth.
Things You Will Need
“Blue Mist” spirea doesn’t require fertilization or soil amendments such as compost. Overly rich soil can damage the shrub.
Wet soil results in crown and root rot. Plant “Blue Mist” spirea in a raised bed if your soil is heavy clay or drains poorly.
Family: Lamiaceae (lay-mee-AY-see-ee) (Info)
Genus: Caryopteris (kar-ee-OP-ter-iss) (Info)
Species: x clandonensis (klan-don-EN-sis) (Info)
Cultivar: Blue Mist
Category: Perennials, Shrubs
24-36 in. (60-90 cm)
24-36 in. (60-90 cm)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
Sun Exposure: Sun to Partial Shade
Danger: Unknown – Tell us
Bloom Color: Light Blue
Bloom Time: Mid Summer, Late Summer/Early Fall, Blooms repeatedly
Foliage: Deciduous, Silver/Gray
Average Water Needs; Water regularly; do not overwater
Soil pH requirements:
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
Patent Information: Non-patented
Propagation Methods: By dividing rhizomes, tubers, corms or bulbs (including offsets). From softwood cuttings. From semi-hardwood cuttings. By serpentine layering
Seed Collecting: N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed
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