Are Rhododendrons Bad for Bees? (Answered)

by Alex Kountry
Updated on

You might want to know the answer to this question “are rhododendrons bad for bees?” for several reasons.

Your reason could be simple curiosity, for academic purposes, for research purposes or maybe you are a beekeeper.

Rhododendrons are good for bees in that they produce nectar which is not toxic to bees. But there are some species of bees that do not like rhododendron flowers simply because of the species. Bees find them attractive and will pollinate with them easily

The answer to this question is not simply a “yes” or a “no” as it depends on several factors such as:

  • The species of the bee in question; and
  • The rhododendron’s species.

Therefore, you can safely say rhododendrons are bad for bees dependent on the species of the bee and the species of rhododendron that bees consume.

Alternatively, you could say that all rhododendrons are not bad for all bees but some rhododendrons are bad for some species of bees.

As you continue to read this article, you will understand better, the effect of rhododendron on bees, the rhododendron that are bad for bees, the bees that rhododendrons are bad for, and lots more.

Are Rhododendrons Friendly to Bees?

Are Rhododendrons Bad for Bees

This species of rhododendron is regarded as the common one, the nectar it produces is not toxic.

However, research has proven that the nectar of this species may negatively affect bees in some countries.

This happens in countries that rhododendron ponticum is an alien species.

Related: Here is an article I wrote on are flow hives bad for bees?

Do Bees Find Rhododendrons Attractive?

Even though the pollen and nectar of certain species of rhododendrons can be deadly to certain species of bees, the bees still find rhododendrons attractive.

You know that nectar and pollen are food sources for bees. The nectar of flowers is sugary sweet; you know bees like sweet things and they use this to make honey.

You could say that honey is nectar that is highly concentrated.

Flowers of Rhododendrons have an abundance of nectar, this invariably means you are sure to find bees buzzing around the flowers.

Which creature on earth does not like an abundance of food.

Bumblebees are especially fond of consuming rhododendrons nectar and pollen.

Do Bees Treat Rhododendron Flowers as Food Sources?

As you already know, the flowers of Rhododendrons are packed with nectar that is food to different species of bees.

This is the case especially when those species of rhododendrons are not harmful to the species of bees in question.

We have discovered that some species of bees treat some species of rhododendrons as their food source.

For example, the native bumblebees in Ireland can safely consume the nectar of rhododendron flowers that are native to Ireland without negative effects.

Are Rhododendrons Liked by Pollinators?

Pollinators are animals that aid in the pollination of flowers, they move pollen from the anther of flowers (which are males) to the stigma of flowers (which are the female organs of flowers).

You most likely have come across this information in elementary school. The relevance of mentioning this here is so that you would know what pollinators are and how they interact with rhododendrons.

Pollinators are mostly flying insects such as flies, butterflies, bees, moths, and wasps.

Pollinators consume the pollen of flowers for several reasons and in the process pollinate flowers.

They are attracted to rhododendrons because the nectar is like a reward to them, during pollination they consume the nectar of rhododendron flowers that like diluted sugar.

Also here is an article I wrote on are neonicotinoids bad for bees?

Why Are Rhododendrons Bad for Bees and Possibly Humans?

Knowing that certain species of rhododendrons are bad for bees you might be curious to know why this is the case.

Rhododendrons have a self-protective mechanism, this works in such a way that the plants produce toxic chemicals. This chemical prevents animals from consuming the leaves of rhododendrons.

The toxic chemicals are also present in the nectar of rhododendrons, this makes it bad for certain species of bees and other pollinators that do not have the tolerance for the toxins in rhododendrons.

However, the level of toxins in invasive rhododendrons is significantly lower than the levels in native rhododendrons.

When bees consume the “toxic nectar” that rhododendrons have they go on to produce the type of honey that is often referred to as “mad honey”.

This type of honey has detrimental effects on humans if consumed in large quantities.

The way “mad honey” would affect you is quite similar to how toxic nectar from rhododendron flowers would affect bees that are not resistant to the effects of such toxic nectar.

 A historical fact is that European armies in times past weaponized this “mad honey”  in wartimes.

They did this by laying barrels of the honey in the path of their opposition, when the soldiers of the opposition would encounter the ‘delicious’ barrels of honey they would consume the honey and the effects of “mad-honey” would set in.

The effects include vomiting and being dizzy for a while.

These effects would eventually fade away, but it would have slowed down the opposition significantly and weakened their soldiers.

The effects rarely led to the death of soldiers but it served its purpose.

Trust humans to make weapons from anything, no matter how subtle or minute its effects would be.

The toxin contained in the flowers of rhododendrons that are invariably transferred to the honey that causes these effects is called ‘grayanotoxins’.

Effect of Rhododendrons/Grayanoyoxins on Humans

Mad honey still affects people to this day: consuming honey made by the Himalayan Giant

Honey bees that make honey from consuming the nectar of rhododendrons could lead to you being temporarily paralyzed for up to a day.

Some people however believe that mad honey could boost sexual performance, this has created a substantial market for mad honey where people seek it for this effect.

We however suggest that you do not attempt this because it could have damning effects on you. Mad honey is not something to be trifled with

What Bees and Insects Consume Rhododendrons?

By reason of the research conducted by Professor Jane Stout in Ireland, it was discovered that the species of bees that visit and consume rhododendrons are predominantly bumblebees.

Ants sometimes visit and consume rhododendrons, so do wasps, solitary bees, and flies.

What are the Exact Effects of Rhododendrons on Bees?

As we discovered when going through the above-mentioned research in Ireland, upon consuming the nectar of rhododendrons honey bees experience paralysis, palpitations and end up dying within a couple of hours of such consumption.

A species of bees known as Mining bees were also experimented on, it was discovered that this species did not die from the effects of rhododendrons as much as honey bees.

They were however not unaffected by it as they became paralyzed. This substantially affected their behavior.

Buff-tailed bumblebees were not affected when tested, this is most likely due to the fact that this species of bee have evolved to develop a resistance to grayanotoxins produced by rhododendrons nectar.

How Many Species of Rhododendron Exist?

There are at least one thousand species and subspecies of rhododendrons, this makes it significantly difficult for the average person to know the toxicity of the rhododendron they encounter.

Knowing the species becomes more important if you are a beekeeper and you are surrounded by rhododendrons.


We know that rhododendrons can be very bad for bees, this however is not a blanket statement.

They are some species of rhododendron that have less toxins as they have evolved to encourage pollination of their flowers, this makes them less toxic to bees.

There are also species and subspecies of bees that have evolved and have grown resistant to the bad effects of rhododendrons, especially bumblebees.

We have attempted to inform you as much as possible about the effects of rhododendrons on bees and if they are bad for bees or not.

So the next time you encounter the question “Are Rhododendrons Bad for Bees? “ you are adequately informed to answer this question.

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About the author

Alex Kountry

Alex Kountry is the founder of HayFarmGuy and has been a backyard farmer for over 10 years. Since then he has decided to write helpful articles that will help you become a better backyard farmer and know what to do. He also loves to play tennis and read books


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