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Ceanothus thyrsiflorus (Blue Blossom)

Blueblossom, Bluebrush, Blue Blossom

Ceanothus thyrsiflorus, Blueblossom, Bluebrush, Blue Blossom, Blue Flowers, Fragrant Shrubs, Evergreen Shrubs
Ceanothus thyrsiflorus, Blueblossom, Bluebrush, Blue Blossom, Blue Flowers, Fragrant Shrubs, Evergreen Shrubs
Ceanothus thyrsiflorus, Blueblossom, Bluebrush, Blue Blossom, Blue Flowers, Fragrant Shrubs, Evergreen Shrubs

The hardiest of the California wild lilacs, Ceanothus thyrsiflorus (Blue Blossom) is a large, upright, evergreen shrub noted for its large fluffy clusters, 8 in. long (20 cm), packed with pale to dark blue flowers dotted with yellow stamens. Blooming from mid-spring to early summer, the flowers are so profuse that they literally cover the shrub, transforming the plant into an explosion of blue. The blossoms are borne on arching branches clad with small, lustrous green, oval leaves. Fast-growing, Blue Blossom is native to the coastal chaparral and rocky, maritime, open, and wooded slopes, bluffs, and flats along the western coast of the United States from California north to Oregon. Its flowers are important for bees, moths, and butterflies, and its seed pods are an important food source for birds and small mammals. Adding exquisite beauty to the landscape, it can be grown in sunny shrub borders, screens, hedges, against walls, and open slopes.

  • Grows up to 15-20 ft. tall and wide (450-600 cm).
  • Thrives in average, moist to dry, well-drained soils in full sun. Appreciates afternoon shade in hot summer areas. Tolerant to salt spray, and poor, shallow, rocky to sandy soils. Established plants need little summer water (once or twice a month). Drought tolerant once established.
  • Excellent choice for wall-side borders, beds and borders, city gardens, coastal gardens, cottage gardens, and Mediterranean gardens.
  • Prune immediately after flowering.
  • Propagate by seed or semi-hardwood cuttings.
  • Keep an eye out for scale insects, honey fungus, and Phytophthora root disease.
  • Native to California, Oregon.

Requirements

Hardiness 7 - 11
Heat Zones 3 - 10
Climate Zones 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Shrubs
Plant Family Rhamnaceae
Genus Ceanothus
Common names California Lilac
Exposure Full Sun, Partial Sun
Season of Interest Spring (Mid, Late), Summer (Early)
Height 15' - 20' (4.6m - 6.1m)
Spread 15' - 20' (4.6m - 6.1m)
Maintenance Low
Water Needs Low, Average
Soil Type Clay, Loam, Sand
Soil pH Alkaline, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Showy, Evergreen
Native Plants United States, Pacific Northwest, California, Oregon
Tolerance Drought, Salt, Dry Soil, Rocky Soil, Clay Soil
Attracts Bees, Birds, Butterflies
Garden Uses Banks And Slopes, Beds And Borders, Hedges And Screens, Wall-Side Borders
Garden Styles City and Courtyard, Coastal Garden, Informal and Cottage, Mediterranean Garden
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Alternative Plants to Consider

Ceanothus integerrimus (Deerbrush)
Ceanothus oliganthus (Hairy Ceanothus)
Ceanothus thyrsiflorus var. griseus (Carmel Ceanothus)
Ceanothus cuneatus (Buckbrush)
Ceanothus ‘Julia Phelps’ (Small Leaf Mountain Lilac)
Ceanothus ‘Remote Blue’ (Mountain Lilac)

Recommended Companion Plants

Fremontodendron californicum (California Flannelbush)
Eriophyllum confertiflorum (Golden Yarrow)
Mimulus aurantiacus (Bush Monkey Flower)
Rhus glabra (Smooth Sumac)

Find In One of Our Guides or Gardens

Stunning Blue Flowers to Enhance Your Garden’s Beauty
35 Flowering Shrubs That Thrive in Full Sun
Ceanothus (California Lilac)
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
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Requirements

Hardiness 7 - 11
Heat Zones 3 - 10
Climate Zones 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Shrubs
Plant Family Rhamnaceae
Genus Ceanothus
Common names California Lilac
Exposure Full Sun, Partial Sun
Season of Interest Spring (Mid, Late), Summer (Early)
Height 15' - 20' (4.6m - 6.1m)
Spread 15' - 20' (4.6m - 6.1m)
Maintenance Low
Water Needs Low, Average
Soil Type Clay, Loam, Sand
Soil pH Alkaline, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Showy, Evergreen
Native Plants United States, Pacific Northwest, California, Oregon
Tolerance Drought, Salt, Dry Soil, Rocky Soil, Clay Soil
Attracts Bees, Birds, Butterflies
Garden Uses Banks And Slopes, Beds And Borders, Hedges And Screens, Wall-Side Borders
Garden Styles City and Courtyard, Coastal Garden, Informal and Cottage, Mediterranean Garden
How Many Plants
Do I Need?
Explore Great Plant Combination Ideas
Ceanothus (California Lilac)
Not sure which Ceanothus (California Lilac) to pick?
Compare Now

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