Robinia pseudacacia

Common Names

Black Locust, False Acacia, Locust, Yellow Locust, Bastard Acacia, Fragrant White Locust, Common Robinia

Summary

Black Locust is a fast-growing, spreading deciduous tree native to the southeastern United States that can reach roughly 12–25 meters in height with a narrow, open crown and deeply furrowed bark; it has dark green pinnate leaves with 7–19 leaflets and bears fragrant white pea-like flowers in pendulous racemes in late spring to early summer, followed by flat seed pods.

In cultivation it tolerates full sun and a wide range of soils, including poor, well-drained conditions, and is drought-tolerant while fixing nitrogen to improve soil; it is valued for erosion control, ornamental use, and as a nectar source for honeybees, with wood durable for posts and fencing; however, vigorous suckering can form dense thickets and the plant is considered invasive in some regions, so removal of suckers and careful management is advised; propagation is by seed or cuttings, and pruning in late summer or autumn helps maintain form.

Lifecycle

Perennial

Height

40-70 feet

Spread

240-420 inches

Hardiness Zones

Zones 4-8

Sunlight Requirements

Ideally Full Sun; light shade is acceptable if full sun isn’t available; also listed as Full Sun, Partial Sun, or Partial Shade.

Soil Type

Moist, well-drained soil

Soil Drainage

Well-drained soil.

Soil pH

6.0-8.0

Bloom Color

White

Bloom Time

Spring to Summer

Foliage Color

Green

Fall Foliage Color

Yellow

Leaf Lifecycle

Deciduous

Growth Rate

Fast growth; young trees grow about 2–3 ft per year and can reach about 3 m in a growing season on good sites.

Seasons of Interest

Spring, Summer, Fall

Propagation Methods

Seeds, Cuttings (root, hardwood, softwood), Suckers/root sprouts, Grafting, Tissue culture, Coppicing and sprouting from stumps/roots, Stump-based propagation, Direct seeding

Attracts Wildlife

Attracts bees and birds