Which Plants Produce Nectar That Makes Honey Toxic For Humans?

It is known that the nectar gathered from different blossoms gives honey a distinct taste, and can also affect the color, thickness and fragrance of the honey.  For example, Tupelo honey is light in color, with a very aromatic with a distinct flavor (popular with mead makers) and it is widely known for its sweetness.  If bee hives are placed alongside oil seed rape flowers, this can cause the resulting honey to crystallize quickly.  Heather produces dark, aromatic and relatively gelatinous honey.  Raspberry and blueberry blossom honey has aromas and flavors reminiscent of the fruit (and also makes good mead).  These kinds of flavors and qualities are popular with, and familiar to buyers.

Honey was used in ancient medicine. However, it is actually possible for bees to gather nectar and pollen from flowers that results in honey which is toxic for humans, or to or at least is unpleasant or bitter tasting.  In fact, the earliest form of known, in a sense, 'chemical warfare' dates back to Turkey in 65 BC, in which the Roman army were tempted with honey made from nectar collected by honey bees from Rhododendron ponticum. Consuming the honey, also known as 'mad honey' can result in severe symptoms which can be fatal.

Plants known to create honey toxic or unpleasant for humans

Below is a list of plants taken from the research paper: The ecological significance of toxic nectar - Lynn S. Adler (OIKOS 91: 409 – 420. Copenhagen 2000).  

(Please note, some of these plants may be present in your country, or not, but this website receives visits from many different countries).

Plant Species & Family Effect On Honey Reference
Aguaria spp.

Andromeda spp

Kalmia spp.

Rhododendron flavum

Rhododendron ponticum

Paullinia australis
Honey toxic
to humans

Azalea pontica

Kalmia latifolia
Honey toxic
to humans
Euphorbia spp.

Arbutus unedo
Honey bitter to
induced nausea
Ledum Palustre
Honey toxic
to humans
Senecio jacobaea
Honey bitter
to humans
Deinzer et al.

Plants toxic for bees

Some plants actually produce nectar that it toxic or detrimental to bees that gather it.  For example, it is known that some species of lime trees can be harmful, especially to bumble bees.  Why some plants may poison pollinators is a subject of debate.

Read more about plants toxic for bees.

You might like these

Home page