Skip to main content
You have permission to edit this article.
Master Gardeners of Napa County: Native Ceanothus is ideal for Napa County
Master Gardeners

Master Gardeners of Napa County: Native Ceanothus is ideal for Napa County

  • Updated

Ceanothus, native to California and very drought-tolerant once established, is ideal for Napa Valley gardens.

Ceanothus is ideal for use in our Napa Valley gardens. The plant is native to California and very drought-tolerant once established. There are almost 50 species in our state and most are evergreen. It blooms all summer with lilac-like blossoms. Among the many types of Ceanothus, also called California lilac, are ground covers and bushes, with both white and blue blooms.

After the first year, Ceanothus does not need to be watered. More Ceanothus have been killed by too much water than not enough. This plant does not need to be loved to death. I was given a Ceanothus sonomensis by a friend on Atlas Peak and I knew it was rare and I did love it to death. After the fire on Atlas Peak in 2017, many seedlings of this species sprouted and there is hope it will survive. It occurs in only place in Napa County.

Ceanothus is a Greek word meaning “spiny plant.” While most of the species are in California, Ceanothus are also found throughout the West all the way to the Rocky Mountains and as far south as Guatemala. In California they grow from near sea level to an elevation of 9000 feet.

If you decide to include Ceanothus in your landscape, learn what keeps this plant happy and what type of plants make good companions. Ceanothus want a sunny location with well-draining soil. Do you want a ground cover or a tall bush or even a small tree? Most Ceanothus appreciate mulch around the root area and some fertilizer occasionally. If possible, provide a sheltered spot away from harsh winds.

I found excellent information on Ceanothus in "Gardening in Summer-Dry Climates" by Nora Harlow and Saxon Holt. The book tells you where each type originated and the zone where it does best. I recommend this book to everyone who wants a drought-tolerant garden. Napa Valley’s USDA Zone is 9 and our Sunset Zone is 14.

Like legumes, Ceanothus are nitrogen-fixing plants. They pull nitrogen out of the air and transfer it to their roots. A bacterium then transfers this nitrogen to the soil. In contrast, many crops take nitrogen out of the soil and the nitrogen has to be replenished with fertilizer. Nitrogen-fixing plants like clovers, lupines, beans and peas are planted in late fall to help keep the soil healthy.

Companion plants for Ceanothus should have the same care requirements. Consider drought-tolerant California natives such as lamb’s ears (Stachys byzantina), lavender, and any of the many varieties of sage and sedum. Even if we get a reprieve from the drought with a wet winter, lack of rain is a long-term issue in our area. So plan your garden carefully, wait for autumn to plant and then hope for rain.

Workshop: Napa County Master Gardeners will conduct a workshop on “The Art of Growing Succulents” on Saturday, July 17, from 9:30-11:30 a.m. via Zoom. Learn how to care for these unique, colorful and unthirsty members of the plant community. Register here:

Napa Library Talk: Napa County Master Gardeners will give a talk on “Planning a Moon Garden” on Thursday, Aug. 5, from 7-8 p.m. via Zoom. Learn about this ancient nocturnal garden theme and pick up some design tips. Register at

Food Growing Forum: Napa County Master Gardeners will present a discussion of “Herbs and Starting Winter Vegetables by Seed” on Sunday, Aug. 8, from 3-4 p.m., via Zoom. Register to receive the Zoom link:

Catch up on Napa County's top news stories

In case you missed it, here is a look at the most-read stories on

Get unlimited digital access to the Napa Valley Register for just $1 for your first 3 months! Enjoy every article without restrictions and find tons of subscriber-only perks, such as access to our daily eEdition. Click here for details!

If you would love to be able to grow your own plants but don’t have space for a garden, have you considered growing herbs on your countertop?

Got Garden Questions? Contact the Help Desk. The team is working remotely so please submit your questions through the diagnosis form, sending any photos to or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email.

For more information visit

Make your house a home

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Related to this story

Get up-to-the-minute news sent straight to your device.


News Alerts

Breaking News