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Robinia pseudoacacia

Common Name(s):

  • Black Locust
  • Common Locust
  • Yellow Locust
Phonetic Spelling
roh-BIN-ee-ah soo-doh-ah-KAY-see-ah
This plant has low severity poison characteristics
See below
Description

The Robinia pseudoacacia, commonly called black locust, is quick growing, medium sized, suckering, deciduous tree that typically grows to 30-50’ (less frequently to 80’) tall. Although originally native to the Allegheny Mountains, it has escaped gardens and naturalized over time to cover much of the United States and southern Canada plus parts of Europe, Asia and South America. At its best, it will grow as a broadly columnar single trunk tree with a narrow oblong crown. It also will grow in suckering thickets.  Young growth on this tree has thorns.

This is a good plant for difficult sites, transplants well, and tends to reseed.  It develops shoots from roots.  It is also a legume, fixes its own nitrogen and is moderately salt tolerant.

The wood from this native is naturally rot resistant and often used to make fence posts and rails.

 

Seasons of Interest: 

     Leaves:       Bloom:   Spring    Fruit/Seed/Nut:  Fall

Insects, Diseases, or Other Plant Problems:  It is susceptible to locust borer (often fatal) and locust leaf miner (browns foliage). Other insect problems include caterpillars, weevils, scale and whiteflies. Possible disease problems include canker, powdery mildew, leaf spots, wood rots and verticillium wilt.

Species trees are sometimes considered to be somewhat weedy. Trees send out long underground root suckers that not only become a maintenance problem but also can disrupt nearby gardening areas.

Small branches of the Black locust fall easily during storms.  Some of its leaves yellow and fall off during times of drought.

Cultivars:
  • Frisia
  • Tortuosa
Tags:
#bees#fragrant#butterflies#deciduous#birds#flowers#wildlife plant#showy#salt tolerant#cover plant#host plant#wetlands#flowering#low flammability#host tree#fire resistant
Cultivars:
  • Frisia
  • Tortuosa
Tags:
#bees#fragrant#butterflies#deciduous#birds#flowers#wildlife plant#showy#salt tolerant#cover plant#host plant#wetlands#flowering#low flammability#host tree#fire resistant
  • Attributes:
    Genus:
    Robinia
    Species:
    pseudoacacia
    Family:
    Fabaceae
    Life Cycle:
    Woody
    Country Or Region Of Origin:
    Eastern and central United States
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    The Black locust is a host plant for the Eastern Tiger Swallowtail, Mourning Cloak, Eastern Comma, Red-Spotted purple, and Viceroy butterflies.  The buds and catkins are eaten by birds.  It provides an excellent leaf cover for birds in wetland sites.   Bees are attracted to its flowers.
    Play Value:
    Wildlife Enhancement
    Particularly Resistant To (Insects/Diseases/Other Problems):
    fire in the landscape.
    Dimensions:
    Height: 30 ft. 0 in. - 50 ft. 0 in.
    Width: 20 ft. 0 in. - 35 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Native Plant
    Poisonous
    Tree
    Leaf Characteristics:
    Deciduous
    Maintenance:
    Medium
    Texture:
    Medium
    Appendage:
    Spines
    Thorns
  • Cultural Conditions:
    Light:
    Full Sun (Direct sunlight 8+ hours a day)
    Partial Shade (Direct sunlight (2-4 hrs) for only part of the day
    Soil Texture:
    High Organic Matter
    Loam (Silt)
    Sand
    Soil Drainage:
    Good Drainage
    NC Region:
    Coastal
    Mountains
    Piedmont
    Usda Plant Hardiness Zone:
    4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Purple/Lavender
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Length:
    > 3 inches
    Fruit Description:
    The flowers are followed by smooth, flat, purple-brown seed pods (to 4-5” long).
  • Flowers:
    Flower Color:
    White
    Flower Inflorescence:
    Catkin
    Flower Value To Gardener:
    Fragrant
    Flower Bloom Time:
    Spring
    Flower Description:
    Fragrant wisteria-like white flowers in pendant racemes (to 8” long) bloom in late spring. They are pea-like and very fragrant.
  • Leaves:
    Leaf Characteristics:
    Deciduous
    Leaf Color:
    Blue
    Brown/Copper
    Green
    Leaf Value To Gardener:
    Showy
    Deciduous Leaf Fall Color:
    Gold/Yellow
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Alternate
    Hairs Present:
    No
    Leaf Description:
    The leaf of the Black locust is noted for its attractive alternate, compound leaves and pendant racemes of pea-like flowers. Its branches are usually armed with short paired spines (to 1.25” long). It has pinnate dark blue-green leaves, with each leaf having up to 23 lance-shaped to ovate leaflets. Leaves turn uneventful yellow in fall.
  • Stem:
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Naturalized Area
    Landscape Theme:
    Butterfly Garden
    Native Garden
    Pollinator Garden
    Design Feature:
    Flowering Tree
    Attracts:
    Bees
    Butterflies
    Hummingbirds
    Songbirds
    Resistance To Challenges:
    Black Walnut
    Drought
    Dry Soil
    Poor Soil
    Salt
  • Poison:
    Poison Severity:
    Low
    Poison Symptoms:
    Depression, weakness, dilated pupils, vomiting, bloody diarrhea, weak pulse, coldness of arms and legs, paleness, and shock.
    Poison Toxic Principle:
    Robin, a phytotoxin; robitin, a glycoside; robinine, an alkaloid.
    Causes Contact Dermatitis:
    No
    Poison Part:
    Bark
    Leaves
    Seeds