It is considered a rare species north of the international border, as most of the valuable coastal land that hosts this plant in the San Diego area has been claimed for development.

The specimens are consistent with C. verrucosus, and apparently were mislabeled from the beginning, representing the San Diego material indicated in the protologue.

In the United States, the distribution of this species is threatened by rampant coastal development, fire suppression, and activities along the international border.

[1] In Baja California, this species is distributed along the Pacific coast from Tijuana to the vicinity of El Rosario.

Ceanothus verrucosus forms a post-fire alliance of vegetation that is present on slopes, ridges, and coastal terraces, often growing in association with chamise Adenostoma fasciculatum, bush-rue Cneoridium dumosum, California buckwheat Eriogonum fasciculatum, laurel sumac Malosma laurina, lemonade berry Rhus integrifolia, and mission manzanita Xylococcus bicolor.