(c) Tom Scavo, some rights reserved (CC BY)
iNaturalist
Black Locust Plant Care
Robinia pseudoacacia L.
Robinia pseudoacacia, also known as black locust, is a deciduous tree known for its distinctive pinnately compound leaves and fragrant white flowers. It is popular among plant enthusiasts for its fast growth rate and ability to attract pollinators like bees.nativeTo: North America
Every 7–14 days
Full sun
0–100°F
30–70%
What Is the Black Locust?
Black Locust (Robinia pseudoacacia) belongs to the Fabaceae family within the Robinia genus. Black Locust is native to North America. Black Locust is also known as False Acacia, Yellow Locust, Acacia.
Black Locust displays a fast-growing tree growth habit, reaching up to 30 inches tall with a spread of approximately 20 inches. Black Locust produces showy clusters of fragrant white or pink flowers.
Leaf size: approximately 6 inches.
How Often Should You Water a Black Locust?
Robinia pseudoacacia requires watering every 7–14 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–14 days
Let soil partially dry between waterings
What Light Does the Black Locust Need?
Black Locust thrives in full sun light conditions. The optimal light range is 2000–10000 lux. Avoid placing Black Locust in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Full sun
2000–10000 lux
What Temperature and Humidity Does the Black Locust Prefer?
Robinia pseudoacacia grows best at temperatures between 0°F and 100°F. Black Locust prefers humidity levels of 30–70%.
Temperature
0–100°F
Humidity
30–70%
What Soil Mix Works Best for a Black Locust?
Well-draining loamy soil with good fertility. Good drainage is essential for Black Locust to prevent waterlogging, which leads to root rot and fungal issues.
How Do You Repot a Black Locust?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Black Locust?
Black Locust can be propagated through seeds, root cuttings.
Fertilizing
Every 8 months
During the growing season
Is the Black Locust Toxic to Pets and Children?
Toxic to Pets & Children
Toxic to humans and pets if ingested
What Pests and Diseases Affect the Black Locust?
Black Locust is susceptible to aphids, caterpillars, leafhoppers. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
What USDA Hardiness Zone Does the Black Locust Need?
Black Locust grows outdoors in USDA Zone 3a – 9b. Native to North America, Black Locust is adapted to warm climates. In cooler regions, grow Black Locust as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 3a – 9b
Keep exploring plants
Black Locust is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Robinia genus — compare its care with other Robinia species on PlantoScan.
Black Locust thrives in bright light and direct sun — see other bright-light plants.
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