Could Stinging Nettles Help Control Varroa Mites?
What new research says - and what UK beekeepers need to know
If you keep bees, you probably don't need an introduction to Varroa destructor. The parasitic mite remains one of the most serious challenges facing honey bee colonies, and controlling it is part of responsible colony management.
Recently, however, an altogether more familiar plant has been attracting attention: the common stinging nettle (Urtica dioica).
A study published in BMC Plant Biology in 2025 investigated whether stinging nettles could have a role in controlling Varroa. The results are certainly interesting - but before anyone heads for the nearest nettle patch and smoker, there are some important things to understand.
What did the researchers actually test?
This wasn't simply a case of throwing fresh nettles into a smoker.
The researchers worked with naturally Varroa-infested honey bee colonies and tested two specific nettle preparations:
Nettle extract: a 20% weight/volume ethanolic extract, applied as a spray.
Nettle smoke: 10g of dried nettle plant material used as smoke.
These were compared with colonies treated with 65% formic acid and with untreated control colonies.
Treatments and mite levels were monitored over a three-week period.
And the results were striking
Treatment | Reduction on adult worker bees | Reduction within sealed worker brood |
Nettle extract | 88.93% | 86.73% |
Nettle smoke | 76.28% | 94.82% |
Formic acid | 100% | 100% |
One result is particularly interesting: nettle smoke produced the lowest reduction in mites on adult bees (76.28%), but a much higher reported reduction within sealed brood (94.82%). Nettle extract performed strongly in both measurements.
The researchers also looked at indicators of stress and mortality in the bees. Under the conditions of this particular experiment, bee mortality was lower in the nettle-treated groups than in the formic-acid group.
Those results certainly make nettles worthy of further research. They do not, however, demonstrate that putting nettles in a smoker is a safe or reliable DIY Varroa treatment.
Promising research.
But promising research isn't the same as proven field practice
This is where a social-media post can lose some rather important context.
The study shows that carefully prepared nettle treatments performed well under the particular experimental conditions used by the researchers. It does not establish that putting an arbitrary quantity of nettles into your smoker will reliably produce the same result.
Questions remain about dosing, preparation, consistency, different colony conditions, environmental factors, residues and longer-term effects.
Most importantly, one study, however interesting its results, isn't the same thing as an established treatment protocol.
From Tristan’s Notebook
This is the sort of research I like to keep an eye on.
Beekeepers have always observed what is happening in the natural world around their colonies, and sometimes science gives us a reason to look again at something very ordinary.
Nettles are hardly an exotic plant in Britain. The fact that researchers have found potentially useful activity against Varroa makes this worth following.
But there’s a big difference between “this deserves more research” and “put nettles in your smoker and you’ve solved Varroa.”
For now, I’d put this firmly in the first category.
What about UK beekeepers?
This distinction matters particularly in Britain. Veterinary medicines used to treat honey bees are regulated by the Veterinary Medicines Directorate (VMD). Its current database contains authorised Varroa products for honey bees using active substances including oxalic acid, formic acid and thymol.
The VMD specifically warns that using homemade or unauthorised preparations as medicines may be unsafe and says that medicines not approved for bees must not simply be used as substitutes; veterinary prescribing provisions apply where an authorised treatment isn't suitable. Honey is, of course, also a food product, making residues and treatment records important.
We have not found a stinging-nettle Varroa treatment authorised for honey bees in Great Britain.
So this research should currently be regarded as interesting evidence for further investigation, not a recommendation from Norfolk Bees to treat colonies with nettles.
So, are nettles the future of Varroa control?
Far too early to say.
What makes this study interesting isn't that it has discovered a replacement for established Varroa treatments. It is that a common plant produced substantial effects against the mite in controlled research – sufficiently substantial to make further work worthwhile.
Future studies may establish whether nettle-derived treatments can be made consistent, safe and practical enough to become part of Varroa management. Or they may reveal limitations that aren't apparent yet.
That's how good beekeeping knowledge develops: observe, test, question - and don't confuse an interesting result with a finished answer.
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