Black locust
Robinia pseudoacacia
Your free fertiliser factory: a fast, tough nitrogen-fixer that feeds the soil, gives rot-proof stakes and floods spring with bee forage. Keep it in check — it suckers and spreads, and it's thorny.
Black locust in a syntropic line
Black locust belongs in the Emergent layer as a Secondary nitrogen-fixing biomass species. They frame the line. Rough in-row spacing starts around 1.6 m in a syntropic row. Good line partners include Almond, Apricot. As a Secondary species it carries mid-term yield and structure while climax trees slowly claim the canopy.
Tolerances and growing conditions
- Strata
- Emergent
- Lifecycle
- Secondary
- Soil preference
- Sandy, Loam
- Soil pH range
- 4.6 – 8.2
- Min. temperature
- -35°C
- Min. rainfall
- 500 mm/year
- Wind tolerance
- Medium
- Frost tolerance
- High
- Growth rate
- Fast
- Irrigation needed
- Low
- Foliage
- Deciduous
- Waterlogging tolerance
- Medium
- Origin
- North America
- Native to Portugal
- No
How to manage it
Fast nitrogen-fixing pioneer with rot-resistant timber and excellent bee forage; coppices and pollards vigorously.
How to propagate
Sow scarified seed or dig root cuttings; both establish readily.
Guidance, not a guarantee — success varies by species and skill.
What to watch out for
Suckers aggressively and is invasive in many regions; thorny; foliage, bark and seeds are toxic to livestock and humans.
Frequently asked questions about Black locust
Is black locust frost-hardy?
Yes for winter cold in many climates — generally hardy to around -35°C when dormant, with high frost tolerance in the catalog. Flowering crops can still lose a season to late frost, so site them carefully.
What soil does black locust need?
It does best on sandy, loam ground, at pH about 4.6–8.2.
How much water does black locust need?
Plan for a rainfall floor around 500 mm/year, plus low irrigation once established.
Can black locust handle wet or waterlogged soil?
It has medium waterlogging tolerance — short winter wet is usually fine, standing water is not.
What should I watch out for with black locust?
Suckers aggressively and is invasive in many regions; thorny; foliage, bark and seeds are toxic to livestock and humans.
Black locust in soil templates
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