Black locust
The tree behind the honey sold across Europe as acacia, which is not an acacia at all. Black locust is a North American legume naturalised across central and eastern Europe, where it produces one of the most reliable and most valuable monofloral crops in the world — and it does so in a window of about ten days, which is why the honey is expensive and why a late frost can wipe out a national harvest.
Where not to plant it
Invasive across much of Europe, and listed as a species of concern in several countries. It suckers vigorously, fixes nitrogen into soils where low fertility is the point, and displaces the grassland and heath communities that depend on poor ground. It is simultaneously one of Europe's most valuable honey trees and one of its more damaging introduced plants, and both statements are true.
Caution
Bark, leaves and seeds contain toxic lectins and are poisonous to horses and to people. The nectar and honey are not affected — this is a distinction worth stating precisely, because the tree's toxicity is regularly and wrongly extended to the honey.
Value to bees
- Nectar
- Very high
- Pollen
- Moderate
- As a honey crop
- Major honey crop — yields a surplus in good years
- Which bees, and why
- Honey bees work it in enormous numbers during the flow, to the near-exclusion of everything else. The flowers are large enough that carpenter bees and bumblebees force them open readily, and short-tongued species frequently rob the base rather than entering.
- Worth knowing
- An exceptional nectar source for a very short period. Pollen is useful but secondary — this is a nectar tree above all.
Flowering
- In flower
- May to June (northern hemisphere)
An intense flow lasting only ten days to two weeks, and highly vulnerable to late frost and to rain during bloom.
- When nectar flows
- When conditions align, the flow is extraordinary — colonies can put on substantial weight in a matter of days. Beekeepers across central Europe move hives specifically for it and time the whole season around this fortnight.
- Year-to-year variation
- Among the most variable major honey crops anywhere. A late frost at bud stage, or heavy rain during the ten-day window, can eliminate the crop entirely across a whole region. Two failed years in succession is not unusual, and this variability is a substantial part of why acacia honey is priced as it is.
What it does to the honey
Very pale, almost water-white, mild and clean with a delicate floral sweetness. Its high fructose ratio makes it the slowest-crystallising common honey, which is the trait most consumers actually recognise it by.
Growing it
- Conditions
- Full sun, tolerant of poor, dry and compacted soil, and fixes its own nitrogen. It thrives on ground where little else will, which is exactly why it was planted so widely and why it now spreads where it is not wanted.
- Size
- 12-25 m tall, occasionally to 30 m, spreading by root suckers into thickets.
- Native range
- Eastern and central North America — the Appalachians and the Ozarks. Naturalised extensively across Hungary, Romania, Bulgaria, Italy, France and China, where it is planted on a very large scale.
- Suits
- Large gardens, Farm scale
- Plant only where suckering is acceptable — it spreads aggressively by root and forms thickets.
- Thornless and non-suckering cultivars exist and are the sensible choice for a garden.
- Wood is exceptionally rot-resistant and was traditionally used for fence posts, which is another reason it was planted.
What it looks like
A medium to large tree with deeply furrowed dark bark, pinnate leaves of oval leaflets, and paired thorns at the base of each leaf. The flowers hang in dense white pea-flower racemes, heavily scented, appearing after the leaves.
Sources
- The World History of Beekeeping and Honey Hunting — Routledge (1999) · Historical text
- HoneyHQ editorial synthesis — HEKNO Ltd · HoneyHQ synthesis
How sources are selected and weighted is set out in the sources and evidence policy.
Guides covering this plant
- Why honey has different texturesRunny, set, creamed, thixotropic and comb are five different things, and only one of them is a processing decision. The rest follow from sugar chemistry and from what the bees put in the jar.
- What makes a honey mildMild honeys are pale, low in minerals and dominated by sweetness. They are the right answer far more often than the honey world tends to admit.
- Why some honeys are rareRarity in honey almost always comes down to botany and weather rather than to deliberate restriction. Understanding the mechanism explains why supply swings so violently from year to year.
- Which flowers make honeyBeing good for bees and producing a honey crop are different things. A honey crop needs a plant that flowers in enormous quantity, in one place, at one time — which most good bee plants do not.
- How plants decide honey flavourNearly everything that distinguishes one honey from another arrives in the nectar. The bee contributes enzymes and evaporation; the plant contributes everything you taste.
- Honey chemistry explainedHoney is a supersaturated sugar solution with a small and consequential fraction of everything else. Almost every practical question about honey resolves into a question about that composition.
- Mild honeys: a guide to the gentle end of the catalogueA shortlist of the honeys that sweeten without asserting themselves, and what distinguishes them from one another when there is so little to distinguish.
Tools for planning planting
- Flowering calendar
What should I plant so that something is always in flower for bees?
- Bee-friendly garden planner
What should I plant in the space I actually have?
- Plant recommendation tool
Which plant fills this specific gap?