Ceanothus California Lilac - Soap Plant

Come May and June each year clouds of vibrant blue and white flowers grace the foothills and regale us with their distinctive aroma. Rhamnaceae (Buckthorn Family) Ceanothus (see-uh-no-thus), the Wild California Lilac is one of the most fragrant and colorful native shrubs on the West Coast. In my mountain community, Ceanothus grows amongst the manzanita, wild rose, Douglas-Fir, and Ponderosa Pine. 

In California we have about 20 species of the genus Ceanothus. These species hybridize to such an extent that the identification of any given one is often difficult that many Ceanothi are simply known as “California Lilac”.

What I find most interesting about California Lilac is that it has a history of being one of the 'soap plants'! Native Indian tribes have long used wild lilac blossoms for soap. When rubbed between your hands with water, the blossom lathers! And even more surprising, it has a nice wintergreen aroma.

In her book “The Wild Flowers of California”, Mary Elizabeth Parsons speaks of an old Mexican hunting guide who called attention to California Lilac blossoms as being an excellent soap. “Taking a handful of them down to the stream, he rubbed them vigorously between his wet hands, and found to his astonishment they made an excellent lather, with a pleasant fragrance of wintergreen.” She continues: “A more delightful way of performing one’s ablutions can hardly be imagined than at the brook side with so charming a soap. It is very cleansing and leaves the skin pleasantly soft.” It was most likely the blooms of C. integerrimus also known by it's common name as Deerbrush, Mountain Birch, White tea-tree and Soap-Bush.

In fact, this is not the only plant known as a soap-plant. A few others share the title, including several species of Chlorogalum, goose-foot, and yucca.

What else makes this native plant so extraordinary?

For one thing, Ceanothus supports local wildlife by serving as an important food source for deer. It's seeds are food for quail. And its flowers are a source of nectar for birds, butterflies and bees. Wild Lilac is also a host plant for the California Tortoiseshell butterfly.

Most California Lilac can be found growing in poor, rocky soil and flourishing in drought stricken areas. They are drought and cold tolerant, and prefer dry soil in full sun to achieve the best blooms. Its extensive root system allows it to anchor in dry, rocky slopes.  

One thing that makes Ceanothus really special is its nitrogen-fixing ability. Most Ceanothi have nitrogen-fixing bacteria in their roots that help to nitrify the soil, thereby reducing the need for fertilization but also enables them to survive drought and wildfires. California Lilac is also considered a pioneer plant because it's among the first to grow back after wildfire.

This is not your floral smelling garden variety of lilac, besides the resemblance in appearance the two are different plants all together.  

I hope you enjoyed learning about this beautiful native shrub. 

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