Theblack locusttree is prized (and despised) for its rapid growth.
It can, however, grow much taller (sometimes 90 feet) and spread rapidly in welcoming landscapes.
So, be sure to consider the liability of black locust trees before planting.
Bob Stefko.
These flowers are frequent stopping points for bees and black locust honey is valued for its rich flavor.
Black locust trees feature irregular branches with stout thorns and feathery leaves.
The tree also produces long, leathery seed pods that appear in the fall and persist throughout the winter.
Bob Stefko.
The seeds themselves are resilient and can remain viable where they fall for up to 10 years.
The fast-growing trees need ample space to grow and should not be planted close to homes or other structures.
Today, the quick-growing tree is primarily used forerosion controland landscape reclamation projects, particularly in arid climates.
This habit allows it to form dense colonies that shade prairies and harm native vegetation.
Choose a spot and dig a hole twice as deep and twice as wide as the plants root ball.
Place your tree in the center of the hole and fill the hole halfway.
Bob Stefko.
Add a little water and then continue backfilling the hole.
Tamp down the soil to secure the tree and water thoroughly.
Light
Black locust trees prefer full sun but tolerate light shade.
Credit: Denny Schrock
Dry, sandy soilno problem.
Compacted soil in an urban areano problem.
Boggy soil that dries occasionally?
Credit: Peter Krumhardt
It grows here too.
The only soil that limits black locust growth is soil that is consistently soggy.
Black locust trees also thrive in temperatures between 32 and 90 Fahrenheit but are hardy in zones 4-9.
This means they can tolerate a wide range of temperatures including those well below zero and above 100 .
That said, extreme heat can cause stunted growth, wilting, yellowing, and scorching.
Extreme cold and frost can damage shoots, cause dark spots, and lead to crooked or diminished growth.
Fertilizer
Black locust trees rarely (if ever) require fertilization.
Pruning
Despite its robust growth, the black locust tree doesnt require much pruning.
Diseased, dead, or damaged limbs can be removed as needed.
This could, in turn, draw harmful insects that may further damage the tree.
Pests and Problems
Borers and black locust leaf miners regularly threaten black locust trees.
However, the tree often fully recovers the following growing season.
In many areas, black locust trees are plagued by internal decay.
This can kill a tree or weaken its structure.
Once weakened, black locust trees can easily break apart in windstorms and become a liability.
A weak tree can damage property or endanger people.
Allow the cutting to dry out in cool, dry sand for three weeks.
Plant your cutting deep enough that the top end is just slightly below the surface of the soil.
Place the pot in full sunlight and keep the soil consistently moist until it begins to sprout.
You must scar or break the hard seed coat to allow germination.
Place the container in a cool, dark location and keep the soil evenly moist as the seeds germinate.
Once they sprout, place your container in a cool, but sunny spot.
Continue to keep the soil moist until you transplant your seedlings into the ground in the spring.
It offers fragrant white flowers and typically reaches 80 feet tall and 50 feet wide at maturity.
It grows 50 feet tall and 25 feet wide in zones 4-9.
It typically grows 30 to 40 feet tall in zones 4-8.
It rarely flowers and is hardy in zones 4-8.
Arborvitaes love black locust trees.
They also prefer full sun but can tolerate partial shade and are hardy in zones 2-7.
Blanket Flower
Like black locust trees,blanket flowerscan easily adapt to poor soils and drought conditions.
Blanket flowers are also native to the tough prairie soil of the western United States.
They thrive in zones 3-10 and are not particular about soil pH.
Blanket flowers like full sun.
They will grow in partial shade but may grow leggy and produce fewer flowers.
Mock Orange
Mock orangeis cold-hardy inUSDA zones 4-8.
The shrubs need full-sun exposure to produce the best flowers but can tolerate partial shade.
Also like black locust trees, they grow rapidly (about 2 feet per year).
At maturity, they are typically 8 to 10 feet tall.
Frequently Asked Questions
Black locust trees grow fast, especially in their early years.
Once established, black locust trees are tough to eradicate.
Large trees can be cut down, but thetree stumpsshould immediately be treated with a concentrated herbicide.
Without treatment, new suckers will continue to appear.
Chemical treatments should also be used on seedlings and suckers (and repeated applications may be necessary).
ASPCA Toxic and Non-Toxic Plants.
North Carolina Extension Gardener Plant Toolbox- North Carolina State University.
Black Locust- Robinia Pseudoacacia.
Invasive Species- Best Control Practices.
Michigan Natural Features Inventory- Michigan State University Extension.
Warne, Amanda.Black Locust (Robinia Pseudoacacia L.) Best Management Practices in Ontario.
Ontario Invasive Plant Council.
PMID: 29321910; PMCID: PMC5756842.
Stone, Katharine R.Robinia Pseudoacacia.
In: Fire Effects Information System.
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
