May Plant of the Month: Ceanothus thyrsiflorus

One of my favorite evergreen Pacific Northwest native shrubs, the Ceanothus thyrsiflorus, is a great plant for screening or filling in a large flower bed. Its mature size can range somewhere between five and twenty-five feet tall with a similar width. 

The variety I am growing in my backyard is from Cistus Nursery and is supposed to be taller than it is wide, maxing out at about fifteen feet tall and only five to seven feet wide. 

The genus Ceanothus is commonly known as the California Lilac because they grow natively in California, though they are not closely related to Syringa, the common lilac family. Ceanothus thyrsiflorus is commonly known as Blue Blossom. 

Its blooms occur in mid-to-late spring, and are beloved by pollinators. The bush can literally be buzzing with bees and other beneficial insects enjoying the beautiful flowers.

The flowers are a bluish purple to white in color, and can range in size from about 2” up to 4” long. The foliage is a pleasant, deep green and appears almost glossy. 

The plant is very drought tolerant, and in fact prefers a well-drained spot with soil that hasn’t been amended too much. 

Although this shrub can tolerate a little shade, it won’t flower as much, so plant this beauty where it will get full sun. Avoid planting in an unsheltered location as strong winds may damage leaves and injure the plant. 

Ceanothus thyrsiflorus generally doesn’t need pruning and looks its best when allowed to keep its natural habit. However, if it has outgrown its allotted space, plan to prune after flowering, typically from late June to frost. 

If you’re looking for a native evergreen shrub, consider Ceanothus thyrsiflorus. It has a lot to offer: evergreen, glossy foliage, beautiful flowers that attract pollinators, low maintenance, and the ability to screen out unwanted views, and its native to the Pacific Northwest. It’s tough not to love Ceanothus thyrsiflorus!