Best grown in coastal conditions; needs summer watering and partial shade inland. Hardy to about 20 degrees F. Grows taller if planted too close together or allowed to mound on other plants. In the book Ceanothus by Dave Fross and Dieter Wilken all plants previously designated as Ceanothus griseus are now considered to be Ceanothus thyrsiflorus var. griseus but we will continue to list it under the older name until this new name gets more widely accepted.

The genus name comes from the Greek word keanthos which was used to describe a type of thistle and meaning a "thorny plant" or "spiny plant" and first used by Linnaeus in 1753 to describe New Jersey Tea, Ceanothus americanus. The specific epithet means "glorious" or "superb". 

The information about Ceanothus griseus var. horizontalis displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant.