North America Native Plant

California Buckthorn

Botanical name: Frangula californica occidentalis

USDA symbol: FRCAO4

Life cycle: perennial

Habit: shrub

Native status: Native to the lower 48 states  

Synonyms: Rhamnus californica Eschsch. ssp. occidentalis (Howell) C.B. Wolf (RHCAO)  âš˜  Rhamnus californica Eschsch. var. occidentalis (Howell) Jeps. (RHCAO2)   

California Buckthorn: A Native West Coast Gem for Your Garden If you’re looking to add a hardy, wildlife-friendly native shrub to your West Coast garden, let me introduce you to California buckthorn (Frangula californica occidentalis). This unsung hero of the native plant world might not have the flashiest name, but ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

California Buckthorn: A Native West Coast Gem for Your Garden

If you’re looking to add a hardy, wildlife-friendly native shrub to your West Coast garden, let me introduce you to California buckthorn (Frangula californica occidentalis). This unsung hero of the native plant world might not have the flashiest name, but it’s got everything you could want in a low-maintenance, eco-friendly garden addition.

What Exactly is California Buckthorn?

California buckthorn is a perennial shrub that’s as American as apple pie – well, at least as West Coast American as you can get. This multi-stemmed woody plant typically grows to a manageable 4-5 meters (13-16 feet) tall, though it can stay smaller or grow taller depending on where you plant it and how Mother Nature feels that particular year.

You might also see this plant listed under its scientific synonyms like Rhamnus californica subspecies occidentalis, but don’t let the botanical name-shuffling confuse you – it’s the same lovely shrub.

Where Does California Buckthorn Call Home?

This native beauty is right at home along the Pacific Coast, naturally occurring in California and Oregon. As a true native of the lower 48 states, it’s perfectly adapted to West Coast conditions and plays an important role in local ecosystems.

Why Your Garden (and Local Wildlife) Will Love It

Here’s where California buckthorn really shines. In spring and early summer, it produces clusters of small white flowers that might look modest to us, but are absolutely irresistible to pollinators. Bees, butterflies, and other beneficial insects flock to these blooms like they’re the hottest restaurant in town.

But the real magic happens after the flowers fade. The plant produces berries that start out red and ripen to black, creating a feast for local birds. It’s like running a bed and breakfast for your feathered friends – they get food and shelter, and you get the joy of watching them visit your garden.

Perfect Spots for Planting

California buckthorn is incredibly versatile and fits beautifully into several garden styles:

  • Native plant gardens (obviously!)
  • Wildlife habitat areas
  • Mediterranean-style drought-tolerant landscapes
  • Naturalized areas where you want a wild look
  • Slopes that need erosion control

Growing Conditions That Make It Happy

One of the best things about California buckthorn is that it’s not particularly fussy. Here’s what it prefers:

  • Sunlight: Full sun to partial shade (it’s flexible!)
  • Soil: Well-draining soil is key – it doesn’t like wet feet
  • Water: Drought tolerant once established, but appreciates regular water the first year
  • Climate: Thrives in USDA hardiness zones 7-10

Planting and Care Tips for Success

Getting your California buckthorn off to a good start is pretty straightforward:

When to plant: Fall is ideal, giving the roots time to establish before the growing season.

First year care: Water regularly to help establish a strong root system. Think of it as an investment in future low-maintenance gardening.

Long-term care: Once established, this shrub is wonderfully self-sufficient. It’s drought tolerant and requires minimal pruning – just remove any dead or damaged branches as needed.

A Few Things to Keep in Mind

California buckthorn has a Global Conservation Status of S5T3?, which means its status is a bit undefined. While this shouldn’t discourage you from planting it, it’s always wise to source your plants from reputable native plant nurseries that practice responsible propagation.

Since specific information about its invasive potential isn’t readily available, it’s generally safe to assume that as a regional native, it won’t cause problems in its native range. However, if you’re gardening outside of California or Oregon, you might want to check with local extension services about appropriate alternatives.

The Bottom Line

California buckthorn is one of those plants that proves native doesn’t mean boring. It offers year-round structure, seasonal flowers, wildlife food, and the satisfaction of knowing you’re supporting local ecosystems. Plus, once it’s established, it pretty much takes care of itself – leaving you more time to enjoy watching the birds and butterflies it attracts.

If you’re gardening in its native range and looking for a reliable, wildlife-friendly shrub that won’t demand constant attention, California buckthorn deserves a spot on your shortlist. Your local pollinators and birds will thank you, and your future self will appreciate choosing such a low-maintenance beauty.

California Buckthorn

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Rhamnales

Family

Rhamnaceae Juss. - Buckthorn family

Genus

Frangula Mill. - buckthorn

Species

Frangula californica (Eschsch.) A. Gray - California buckthorn

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA