Ceanothus, commonly known as California Lilac

Family: Rhamnaceae (Buckthorn family)
Genus: Ceanothus
Species: there are many, but choose carefully for hardiness!
Consider:
C. americanus,
C. gloriosus, or
C. velutinus

A few days ago a landscape contractor of my acquaintance asked me for the name of a low-growing evergreen shrub he’d spotted in several yards on South Hill in Bellingham. He was smitten with its dark green leaves and small clusters of blue flowers that he said “looked a little like lilac blossoms.” Well, at that moment Ceanothus was chosen as Plant of the Month for October. As we’re all concerned about sensible water use and what is forecast to be a dry winter heralding, perhaps, drought conditions next year, Ceanothus is a plant that comes to mind as actually thriving in dry summer conditions and poor soil, once it is established.

If you’ve ever visited the coastal areas of central California, you’ve no doubt seen the expanses of Ceanothus throughout that region. It’s a common sight from Big Sur to Point Reyes, providing a fine example of a native plant that has been incorporated admirably into landscape settings. Tolerant of wind and of salt spray, its deep green, crinkly leaves hold their appearance whatever the exposure, so long as it is planted in the sun and in soil that drains well. In fact, neglect is the treatment it seeks. This is a plant that can quickly be killed by kindness. Even a “regular” amount of fertilizer, soil that’s too rich, too much water in the summer (or any standing water at all)—and you’ll have an ex-Ceanothus fit only for the compost bin.

When it’s properly neglected, Ceanothus rewards with stunning flowers that do look a bit like small lilac blossoms, its rich green foliage, and a lovely form. Some species are prostrate and sprawl, others stand like sentinels, upright and proper. All good things have their downside, however; and in the case of Ceanothus, it’s the question of hardiness. Look carefully to find one of the species and particular varieties that will reliably withstand our Pacific Northwest winters. New, hardier types are being developed so that we gardeners in the Northern climes can enjoy this wonderful plant. Do a bit of research, seek them out, and choose carefully, sticking with varieties that are grown and tested in our area. It’s not surprising that South Hill in Bellingham provides a hospitable home for Ceanothus. That neighborhood is one of our most sheltered microclimates. What will prosper there might not last through January in Sumas. Many Ceanothus are described as hardy only to USDA Zone 6—that means to a minimum temperature of minus 10 degrees. Combine the cold of a Northeaster with a three-day blast of wind blowing down from the Fraser River valley, and it adds up to a dead plant. Even when you find a type that suits, take the precaution of planting it in a sheltered location, perhaps even against a wall facing south or west.

More than 40 species of Ceanothus are native to North America. Beyond the domesticated evergreen species and named cultivars, there are several interesting wild forms available from specialty catalogs and seed sources featuring native plants. Many of these are deciduous, with white rather than blue flowers. One that is certainly hardy here is C. americanus, commonly known as New Jersey tea because yes, its leaves were used as a substitute during the Revolutionary War. It also has medicinal properties; its astringent roots were used to staunch bleeding from wounds and to stop hemorrhaging during surgery in field hospitals. It flowers from May to July and holds its very interesting fruit from August to October. It’s a small shrub, less than three feet tall. Butterflies love it. So do deer. I realize this is mixed news for most of you, but who knows, it might even distract them from your tulips…although I have absolutely no research-based information about that. I suppose you’d have to survey the deer.

Another wildflower form with white blooms is C. velutinus, known as Tobacco Brush. C. sanguineus is a choice species, hard to find in nurseries, particularly noteworthy for its bright red stems in winter. Erect, deciduous, loosely branched C. thrysiflorus has blue flowers and is commonly called Blueblossom. It can grow to a formidable size, although it is likely to stay much less than 20 feet tall in our climate. C. gloriosus and C. griseus are smaller, both with deep green, almost blue foliage, and lively blue flowers. Both are reputed to do well here, at least in Bellingham. In the county, C. griseus might be the better choice, if you’d like to give Ceanothus a try.

And is it worth it, to try out a plant that might be only marginally hardy? This is one of the few cases in which I’d answer with a resounding “yes.” Ceanothus is a lovely native, with an interesting history (not to mention its nitrogen-fixing properties), and it makes a handsome addition to the garden. Let me put it this way: if you’ve been able to keep rosemary alive in your garden throughout the winter, then you’ll probably be able to enjoy season after season of Ceanothus. Choose the variety and the site carefully, water it well until it’s established, and then sit back and marvel at the beauty sometimes brought about by benign neglect.

**A short postscript from Cheryll: I’m looking forward to meeting many of you at the graduation celebration dinner in November. It’s an honor to be asked to speak at that event. I’ll be talking about garden trends, what’s old, what’s new, what’s tried, what’s true. There will be plenty of time for your questions, and I’ll be counting on John Van Miert to help me answer them!!