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California buckthorn

Frangula californica · Rhamnaceae

California buckthorn (Frangula californica)
Photo: no rights reserved · CC0 · via iNaturalist

California buckthorn (Frangula californica) is a perennial shrub in the Rhamnaceae family. It is native to North America. USDA records it as hardy in zone 7 and warmer, down to about 7°F.

At a glance

Typeshrub Derived
Lifecycleperennial USDA
Native statusnative USDA
Mature height5 ft USDA
Lightfull-sun USDA
Water needmedium USDA
Growth raterapid USDA
Soil pH6–8.3 USDA
BloomApril–May USDA
Flower colorGreen USDA
Hardiness zones7 and warmer USDA
Guild layershrub Derived
Nursery availabilityRoutinely Available USDA

USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.

Growing conditions

It needs full sun. USDA rates it as having moderate water needs. Its drought tolerance is rated high. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 6 to 8.3 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 7.

Size and growth

At maturity it reaches about 5 ft, making it roughly waist to chest height. It grows quickly.

Bloom period

USDA records a bloom period of April through May. Flowers are green.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is green, medium in texture. Its flowers are not conspicuous — a plant for form and foliage. Its fruit or seed heads are conspicuous, extending interest past flowering. Its active growth period is spring and summer. Its winter foliage is dense, which makes it useful for year-round screening. USDA rates its lifespan as long.

What the site needs to provide

USDA records it across sites receiving 14 to 24 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 180 frost-free days to finish its season. It roots to at least 16 inches. Fertility requirement: medium.

Propagating it

Propagate it from seed, bare root and container stock. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It spreads vegetatively at a moderate rate.

Resilience and wildlife

Browsing animals rate it barely palatable — the sourced basis for calling it deer-resistant. Its fire tolerance is rated high, and it can resprout after damage. Its growth form is recorded as multiple stem.

Role in a guild

Shrub layer. In a layered planting this is woody mid-level structure between the understory and the ground. The layer is derived by a fixed rule from growth habit and mature height.

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Tags

evergreendrought-toleranthedgesandy-soildeer-resistantspreadingnativefull-sunfast-growing

Related plants

Others in Frangula

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol FRCAC5, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.

Read our full data sources and methodology.

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