Several ancient Greek texts provide accounts of people being poisoned by honey that texts suggest was made from the nectar of rhododendron or oleander plants  Honey made from such nectar can cause the effects the texts describe, but only if eaten fresh, since the honey loses its toxicity within a few weeks of being made
In Greece, rhododendrons and oleander bloom only in springtime, when they are the predominant sources of nectar
The incidents of honey poisoning that are related in the ancient texts occurred in the springtime or in the early summer