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bristly locust

Robinia hispida · Fabaceae

bristly locust (Robinia hispida)
Photo: (c) Tom Norton, some rights reserved (CC BY) · CC BY · via iNaturalist

bristly locust (Robinia hispida) is a perennial shrub in the Fabaceae family. It is native to North America. USDA records it as hardy in zone 4 and warmer, down to about -30°F.

At a glance

Typeshrub Derived
Lifecycleperennial USDA
Native statusnative USDA
Mature height7 ft USDA
Lightfull-sun USDA
Water needlow USDA
Growth raterapid USDA
Soil pH3.5–7.5 USDA
BloomMay–June USDA
Flower colorPurple USDA
Hardiness zones4 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 low water needs once established. 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 3.5 to 7.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 4.

Size and growth

At maturity it reaches about 7 ft, making it a plant that will finish above head height. It grows quickly.

Bloom period

USDA records a bloom period of May through June. Flowers are purple.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is green, coarse in texture. Its flowers are not conspicuous — a plant for form and foliage. Its active growth period is spring and summer. USDA rates its lifespan as moderate.

What the site needs to provide

USDA records it across sites receiving 32 to 60 inches of annual precipitation. It needs at least 160 frost-free days to finish its season. It roots to at least 20 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.

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. It spreads vegetatively at a rapid rate.

Resilience and wildlife

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

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

deciduousdrought-tolerantsandy-soildeer-resistantspreadingnativenitrogen-fixerfull-sunfast-growing

Related plants

Others in Robinia

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol ROHIF8, 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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