- Plant Characteristics: Known for its rapid growth, fragrant white flowers, and compound leaves. It has a rugged appearance, with deeply furrowed bark and spines on younger wood.
- Growing & Care: Prefers full sun and well-drained soil. Tolerates poor soils and urban conditions. Drought-resistant once established, but benefits from occasional deep watering.
- Tips for New Gardeners: Suitable for creating fast-growing shade or screening. Handle with care due to its thorns. Note: It's considered invasive in some areas, so check local planting advisories.
Robinia pseudoacacia, commonly known as Black Locust, is a robust, deciduous tree prized for its rapid growth, striking spring flowers, and hard, durable wood. Native to the southeastern United States, this versatile tree serves various purposes, from timber production to ornamental landscaping.
Black Locust typically grows to a height of 30 to 50 feet (9 to 15 meters), and sometimes even up to 80 feet (24 meters), with a spread of about 20 to 35 feet (6 to 11 meters).
Its dark green, pinnately compound leaves provide a graceful canopy, under which spring brings clusters of fragrant, white flowers.
Gardeners favor Robinia pseudoacacia for its resilience, ability to fix nitrogen in the soil, and its attractiveness to pollinators.
Hardy in USDA Zones 3 to 8 (RHS H6, very hardy in most parts of Europe), it's an excellent choice for urban landscapes, street trees, or as a fast-growing windbreak or screen.
How to Grow Robinia pseudoacacia in the Garden
Black Locust prefers a location with full sun. It adapts well to various soil conditions, tolerating everything from well-drained sand to clay, and even poor, dry, rocky soils.
Propagation of Robinia pseudoacacia is typically achieved through seeds, which need to be scarified and soaked in hot water before sowing.
Once established, Black Locust requires minimal care. It is drought-tolerant and generally needs little to no supplemental watering.
Pruning can be done in late winter to early spring to maintain the desired shape and size.
While Robinia pseudoacacia is a robust tree, it can be susceptible to locust borers and leaf miners. Regular inspections and prompt treatment can keep your tree healthy.
Also, note that while the flowers are edible, and sometimes used in fritters or pancakes, all other parts of the tree, particularly the bark, seeds, and leaves are toxic if ingested. Therefore, it is best planted in a location where pets and children won't be tempted to chew on it.
Title: Quick Robinia pseudoacacia Growing and Care Guide
Scientific Name: Robinia pseudoacacia.
Common Names: Black locust, False acacia.
Growing Zone (USA / UK Hardiness): USDA Zones: 3-9. RHS Hardiness Rating: H6 (Hardy – Very cold winter).
Best Used For / Garden Location: Ideal for street or lawn tree, or for erosion control. Prefers full sun locations.
Plant Details
Life Cycle / Plant Type: Deciduous tree.
Plant Height: 30-50 feet (9-15 meters).
Plant Spread: 20-35 feet (6-10.5 meters).
Blooms: Late spring to early summer.
Flower Details: Fragrant, white, pea-like flowers arranged in drooping clusters.
Leaf Foliage: Pinnately compound, bluish-green leaves.
Fruit: Legume pod, 2-4 inches long (5-10 cm), containing hard-coated seeds.
Growing Conditions and Location
Best Light Conditions: Full sun.
Suitable Soil Types: Prefers well-drained, deep, fertile soil, but adapts to a wide range of soil conditions.
Sowing, planting: Plant bare root or balled-and-burlapped trees in late winter or early spring.
Germination time: Seeds typically require scarification to germinate, which may take several weeks.
Propagation: Propagate by seed or suckers.
Plant Care: Water regularly during first growing season. Once established, it's drought-tolerant. Prune in late winter.
Growing in pots and containers: Not suitable for containers due to its size.
Growing as a House plant: Not suitable as a houseplant.
Further Information
Miscellaneous: Resistant to deer. Known for its invasive nature in some regions.
Pests and diseases: Watch for locust borer and leaf miners. Susceptible to heart rot.
Common Cultivars / Varieties: 'Frisia' has bright yellow-green foliage. 'Purple Robe' produces deep pink flowers.
Family: Fabaceae, the Pea/Legume family.
Native: Native to the southeastern United States.
References and Further Reading: Missouri Botanical Garden: Robinia pseudoacacia; RHS guide to False acacia.
Common Questions
Is Robinia pseudoacacia invasive in the USA, if so in which states?
While native to the USA, Robinia pseudoacacia can be invasive in some regions due to its ability to spread through its suckers and seeds. States where it is invasive include many parts of the Midwest and Northeast, it should not be planted in these areas.
How do I remove Robinia pseudoacacia from my garden?
Removing Robinia pseudoacacia requires cutting the tree down and then grinding or chemically treating the stump to prevent suckering. This is a large task often best left to professionals.
Summary
Robinia pseudoacacia, native to the United States, thrives in full sun and tolerates a variety of soils, including poor and dry ones. This fast-growing tree is known for its durability and fragrant spring flowers.
I hope that you have enjoyed reading this guide on how to grow Robinia pseudoacacia. You may also enjoy the following tree growing guides: How to grow Olives, Rain tree, and Holly Oak in the garden or landscape setting.
