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Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Black locust (Robinia pseudoacacia L.), also called yellow locust, is valued in construction for hard, decay-resistant wood used in posts, poles, ties, and decking. It also spreads readily, and whether it is considered native or invasive depends on where you live. Before planting or sourcing it, check local status and consider the site, intended use, and nearby people and animals.
How do I identify a black locust tree?
Black locust is a deciduous tree in the legume family. Identify it by looking for several traits together rather than relying on a single feature:
- Flowers: Fragrant, whitish flowers hang in showy clusters after the leaves emerge, typically in May or June, according to the USDA Forest Service species account.
- Fruit: The flowers are followed by flattened, oblong pods that ripen in September and October.
- Growth habit: It can form dense groups of stems from root suckers, especially where it has spread beyond planted trees.
Flowering and fruiting dates can vary with local conditions. Similar locust species can be confused with black locust, so compare multiple characteristics and consult a regional identification guide such as Iowa State University Extension’s locust guide.
Where is black locust native, and where does it grow?
The USDA Forest Service describes a disjunct native range in parts of the Appalachians, Ozarks, and Ouachitas. The eastern section extends from central Pennsylvania and southern Ohio toward northeastern Alabama, northern Georgia, and northwestern South Carolina; the western section includes the Ozark Plateau and Ouachita Mountains. The original extent is not precisely known. Planting has allowed the tree to naturalize across much of the United States, southern Canada, and parts of Europe and Asia.
#1 Best Overall
- BEAUTIFUL BLACK LOCUST: It's fragrant white flowers are beloved by bees. Attractive wood is popular as lumber.
- FAST GROWING TREE SPECIES: Known for relatively rapid growth compared to many hardwood trees. Establishes quickly and begins developing height early in its lifecycle.
- FLOWERING TREE CHARACTERISTICS: Produces hanging clusters of white flowers in late spring. Blooms add seasonal visual interest and contrast against green foliage.
- MATURE SIZE AND STRUCTURE: Trees can reach 30–70 feet tall with a spread of 20–35 feet at maturity. Develops an open canopy with compound leaves.
- SUNLIGHT REQUIREMENTS: Performs best in full sun with at least 6 hours of direct light daily. Adequate sunlight supports growth and flowering.
Black locust grows quickly when young, fixes nitrogen, and has been used on disturbed sites for reclamation and erosion control. It performs best on suitable, well-drained, fertile sites; poorly drained or compact soils are problems. Its ability to spread means that restoration or erosion-control benefits should be weighed against the risk of unwanted thickets.
Is black locust invasive?
It depends on location. Black locust is native to parts of the United States but has spread into regions outside its original range. For example, the Minnesota Department of Natural Resources describes it as non-native to the Upper Midwest and spreading there. The Wisconsin Department of Natural Resources notes that it can form dense clonal groves and that control can be difficult. USDA guidance also describes state-specific invasive, noxious, or regulated classifications.
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- Black Locust Seeds for Planting: Grow Robinia pseudoacacia from fast growing flowering tree seeds for fragrant white spring blossoms, compound foliage and a spreading shade canopy. These tree seeds are useful for large landscapes, pollinator plantings and naturalized areas where appropriate
- Robinia Pseudoacacia Flowering Tree Seeds: Black Locust produces hanging clusters of fragrant pea shaped white flowers in spring that are highly noticeable against fresh green foliage. As a legume, the species forms associations with nitrogen fixing bacteria around its roots
- Fast Growing Shade Tree: Young Black Locust trees can grow rapidly under favorable conditions and eventually develop an open irregular crown. Mature bark becomes deeply furrowed, adding distinctive texture to older trunks and branches
- Important Planting Consideration: Black Locust can spread vigorously by seed and root suckers and is considered invasive in some regions outside its native range. Check local recommendations before planting and choose a site where its growth and potential spread can be managed
- Scarify Hard Seeds Before Sowing: The hard seed coat generally requires scarification followed by soaking before planting. Grow in full sun and well drained soil, provide regular moisture during early establishment and allow adequate room for developing trees | 100 Seeds
Black locust spreads both by seed and root suckers. A planted tree can therefore lead to new stems beyond its original footprint, and cutting stems may not prevent regrowth from roots. Before planting or removal, check current rules and guidance from your state or local natural-resources agency; classifications and control requirements can change.
What is black locust wood used for?
Black locust heartwood is hard and notably resistant to decay. Its construction and outdoor uses include fence posts, poles, railroad or landscaping ties, decking, and trellises. Utah State University Extension describes the heartwood as yellow to golden-brown and notes its use for posts and ties.
Rank #3
- BEAUTIFUL BLACK LOCUST: It's fragrant white flowers are beloved by bees. Attractive wood is popular as lumber.
- EASY TO GROW: Growing instructions included. Seeds come ready to plant.
- FAST-GROWING HARDWOOD TREE: Establishes quickly and develops height faster than many hardwood species. Suitable for long-term planting where early growth is important.
- SEED POD DEVELOPMENT: After flowering, flat seed pods form and mature through summer, typically 2–4 inches long. Pods dry and release seeds naturally in fall.
- COLD HARDY AND ADAPTABLE: Hardy in USDA Zones 4–8 and tolerates a range of soil types, including lower fertility soils. Performs best in full sun with well-draining conditions.
The USDA Forest Service also lists mine timbers, ship timber, insulator pins, boxes, crates, pegs, stakes, fuelwood, and pulp among its uses. Other reported uses include shelterbelts, reclamation plantings, and honey production. A Maryland USDA Natural Resources Conservation Service guide notes black locust honey as an important product in several European countries; the label “acacia honey” alone does not establish that honey comes from black locust, so check the producer and origin.
Is black locust toxic to dogs, horses, or livestock?
Black locust contains toxic compounds. The Minnesota DNR identifies leaves, stems, bark, and seeds as toxic parts. The USDA Natural Resources Conservation Service cautions that toxicity can vary and that excessive consumption can harm livestock. These warnings do not establish a safe amount of plant material for pets or livestock, so do not treat black locust as general-purpose forage or edible plant material.
If an animal or person may have eaten part of the tree, contact a veterinarian, poison-control center, or medical professional for advice rather than relying on this species overview.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Can I plant black locust in my area?
Plant only after checking local status and deciding whether the tree’s traits match your site and purpose. Its rapid early growth, nitrogen fixation, and durable wood can be useful, but root suckering and seed spread can create management problems. Poor drainage or compacted soil also make a site a poor fit.
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- Grow your own Black Tupelo (Nyssa sylvatica) — a.k.a. Black Gum — a medium-sized deciduous tree native to eastern North America
- 100% guaranteed: If your seedling perishes, we are happy to provide a replacement small-sized seedling for just the cost of shipping/handling ($4.60)
- Seed-grown without poison or pesticides at our nursery on California's Redwood Coast
- Transplanting and care instructions included
- Trees can provide a natural barrier against high winds, temperatures, noise pollution and soil erosion, all while benefiting local air quality, wildlife and property values — a Jonsteen seedling will only grow in value and beauty!
- Confirm whether black locust is native, invasive, restricted, or otherwise regulated where you live.
- Consider whether a spreading tree is appropriate near gardens, natural areas, property boundaries, or infrastructure.
- Match the species to the outcome you need: durable wood, reclamation, erosion control, shade, or pollinator forage.
- Account for toxic plant parts if children, pets, or livestock have access to the planting.
The Forest Service’s 1990 account reports that black locust begins producing seed at about age six, good seed crops occur at intervals of one to two years, and best seed production is reported from ages 15 to 40. It also reports dry seed viability for up to 10 years when stored in closed containers at 0–5 °C. These are source-specific figures, not a universal planting forecast. The account describes a seeding rate of 2.2–3.4 kg/ha (2–3 lb/acre) for broadcast or hydroseeded reclamation mixes; that rate is not general advice for residential planting.
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