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A picture of a Californian Lilac 'Cool Blue'

Californian Lilac 'Cool Blue'

Ceanothus thyrsiflorus 'Cool Blue'

Also known as

Blue Brush 'Cool Blue'

Photo by GardeningExpress (All rights reserved)

Full Sun
Easy care
Moderate watering
Frost Hardy

H4

RHS hardiness

-10°C

Minimum temperature

Expected size

Height
Spread

1.2m

Max

1.5m

1m

Min

1.2m

10 years to reach maturity

Flowering

  • spring
  • summer
  • autumn
  • winter

Californian Lilac 'Cool Blue' Overview

Ceanothus thyrsiflorus 'Cool Blue' is an upright evergreen bushy shrub cultivar, forming a rounded shape. Its leaves are ovate, toothed, veined and have a dark green centre, surrounded by wide creamy-white margins. Contrasting with the foliage, profuse clusters of violet-blue flowers appear in spring and early summer. Commonly known as Californian Lilac 'Cool Blue', the name California Lilac is shared with most plants in the genus Ceanothus. Its beautiful eye-catching blue flowers are a joy to see towards the start of summer. Suited to most garden styles and situations, Ceanothus thyrsiflorus 'Cool Blue' likes a sheltered position in full sun and some shade is helpful in very hot, dry weather; and it likes well-drained soil that is on the alkaline side of neutral. Lightly prune after flowering.

Common problems with Californian Lilac 'Cool Blue'

Phytophthera root disease may also be a problem.

How to propagate Californian Lilac 'Cool Blue'

Cuttings

Semi-hardwood/semi-ripe

Special features of Californian Lilac 'Cool Blue'

Attractive flowers

Attractive leaves

Drought resistant