Ceanothus In The Garden

By Mary Anderson, Master Gardener

Distinctive to California´s wildflower panorama are wild lilacs, or Ceanothus. Native to chaparral zones, especially near the coast, this exuberant shrub blooms with masses of tiny white, blue or lavender flowers.

There are 43 species of evergreen ceanothus—ground cover to small trees. The trick is finding a variety that fits your site. While most ceanothus can be shaped by tip pruning (performed gratis by Bambi in the wild) and cleaning out interior or low dead growth, they resent serious hacking.

All need full sun and well-drained soil. In the garden, they are easily satisfied by one or two deep waterings a month when established. On a hilly site, drainage is not a problem. But if you have a flat area where water collects, bypass ceanothus and plant a riparian shrub instead. Mounding the soil and mulching are also good practices.

Foliage is attractive and evergreen, with leaves tiny to over two inches long. In general, the smaller and more prickly or leathery the leaf, the greater the deer resistance. The lovely Carmel Creeper, Ceanothus griseus horizontalis ‘Yankee Point´ with large glossy leaves and large clusters of medium blue flowers, is a magnificent groundcover but useful only where deer do not have access. However, Ceanothus gloriosus ‘Anchor Bay´ has a similar dense ground covering habit, but with tough spiny leaves it is not as beloved by Bambi. It is one of the most useful varieties for our foothill gardens.

Ceanothus is useful in the transition zone, where more intensely cultivated and watered “house gardens” blend into wild landscape. This area should be minimally watered, widely planted and managed to control deadwood, weeds and litter to reduce fire hazard. Companions are toyon, coffeeberry, groundcover manzanitas, flannel bush, spice bush and carpenteria.

One of the largest forms is Owlswood Blue, reaching 10 feet as a large arching shrub or, with training, even a small tree. This variety requires protection from browsing until it gets quite tall, as it has large tasty leaves. Four-to-six-inch spike-like clusters bear dark blue flowers. Ceanothus thursifloris ‘Blue Blossom´ is a hardy form reaching 15 feet, while ‘Snow Flurry´ is a bit shorter, with white flower clusters. ‘Blue Jeans´ reaches 7-9 feet, with small dark green leathery leaves and loads of powder-blue clusters. It has good deer resistance, tolerates heavier soils and summer water, and takes shaping better than other forms. ‘Frosty Blue´ is another large Ceanothus with small dark green leaves and wonderful two-to-three-inch spike-like clusters of dark blue flowers “frosted” with white.

Among the medium sized varieties, ‘Dark Star´ reaches about six feet but spreads to 10, with excellent deer resistance. Tiny, almost black-green leaves show off deep cobalt blue blooms. ‘Concha´ is a cultivar with deep blue clusters, very garden-worthy, accepting summer water more graciously.

Let´s digress on the “summer water” issue. Most ceanothus, being plants of the hot dry chaparral, have a survival mechanism called leaf drop. Like overloaded fruit trees, sacrificing some of their crop to successfully mature the rest, native shrubs often shed foliage to survive the heat stress of summer. When real pounding heat begins, usually late in June, some leaves yellow, then drop. Our reaction—run for the hose. Their reaction—root rot and die. This is a natural survival response, an adjustment. If you have the plant on a weekly or bi-weekly water cycle, keep it up but don´t increase. If the plant is fully naturalized, growing without supplemental water, wish it “good night.” It will awaken with the fall rains. My ‘Dark Star´ behaves like this.

Among my favorite ceanothus are the C. gloriosus family. They all have dark green prickly hollylike leaves and excellent deer resistance. One of my most successful uses of this plant was to cover a very large area with awful subsoil. The home owner borrowed soil from another area on his property and we created 2 x 4 foot mounds at 10 foot spacing, each planted with one ‘Anchor Bay´ ceanothus, with an occasional deer grass, or Muhlenbergia rigens, for accent. The effect was one of a rolling sea of deep green that flushed blue in the spring.

Another lovely form is ‘Emily Brown,´ a mounding shrub about three feet high with attractive reddish stems. And the baby of the family is a form called ‘Hearts Desire,´ dense and low with tiny shiny leaves.

Ceanothus ‘Joyce Coulter,´ has a large mounding form, 4 by 8 feet in my garden. With medium green leaves, it is covered in spring with wildly fragrant medium blue three-inch flower spikes. This is one of the best bloomers, but she is not highly deer resistant.

These lovely shrubs are best planted in the fall, ready to take off and put on growth before blooming in the spring. They´ll be available at the CNPS fall plant sale on October 15th, 9:00 a.m. to 2:00 p.m., WestAmerica Bank parking lot in East Sonora.

See you at the plant sale and see you in the garden.

Mary Anderson, a Calaveras County Master Gardener and owner of Lost Hills Nursery, has spent the last 25 years getting to know California native plants on her 10-acre property and propagates many native plants from the seeds of her ‘mother plants´. As one of the original members of the Sierra Foothills Chapter of the California Native Plant Society she shares her wonderful knowledge of native plants at the twice-yearly Native Plant Sale. Come meet Mary on Saturday, October 15th and let her inspire you to plant natives in your garden.