Ceanothus species (California Lilac, Wild Lilac)
Golden West College Native Garden – Plant of the Month 2010 March
By Dan Songster
If you are visiting the GWC Garden this month you will notice a wonderful blue flowered plant-the Ceanothus! In California we have about 60 native species and varieties of Ceanothus (with many other cultivars to choose from). What riches to choose from! The straight species are often used in restoring wildlands and the cultivars (those with names surrounded with half quotes like Ceanothus ‘Joyce Coulter’), are commonly used in gardens since they generally take garden conditions better.
Type: Evergreen shrub
Light: Full sun to partial shade
Soil: Well drained (but somewhat adaptable)
Water: Drought tolerant
Environment: Most enjoy full sun and prefer well-drained soil, though they do pretty good in our clay soil here at GWC Native Garden. On a hilly site, drainage is not so much a problem, in fact if you have flat area with relatively heavy soils, mounding the soils and planting on top can be good way to grow them. But don’t plant them in a low, flat area where water collects or they will rot away. They are easily satisfied by one or two deep waterings a month once established.
Flower and Leaf: Though several Ceanothus have white flowers, their dominant flower color is blue-which is certainly a rare color in the garden. This fact alone is reason enough to plant our native Ceanothus. The blue is usually a truer blue than the common name, wild lilac, would suggest although one of the fun things about Ceanothus is that the flower colors range from a light frosted blue to almost cobalt (and yes there are a few lilac colored varieties). Some are nearly iridescent. The foliage ranges from glossy greens with smooth edges to duller green small with toothed margins.
Size
Besides choosing what shade of blue, you can also select what size you would like since Ceanothus range from ground huggers to small trees. Choosing the right size is important since they do not like being severely cut back. Light tip pruning (like deer nibbling in the wild) is fine, but no hacking!
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- Some of the large tree-like Ceanothus include: C. arboreus,; C. thrysiflorus ‘Snow Flurry’, C. ‘Ray Hartman.
- Medium shrubs include: C. ‘Concha’, C. ‘Dark Star’, C. ‘Julia Phelps’, C. ‘Wheeler Canyon’, C. impressus, and C. ‘Joyce Coulter’.
- Lower Groundcovers include C. ‘Anchor Bay’, C. ‘Heart’s Desire, C. ‘Centennial’, C. ‘Yankee Point’ and C. maritimus.
Habitat: These plants are also good habitat plants drawing several butterflies which use the flowers for nectar but also lay their eggs on them as larval host plants! And when the plants produce their small shiny seeds several of the seed eating birds stop by and feast.
In short if you want a blue flowering shrub, that attracts good wildlife, needs little care or water, and blooms its head off every spring-then choosing one of our native Ceanothus will make you happy.
Note: The book “Ceanothus” by David Fross and Dieter Wilken is THE book on these wonderful plants.