Advice for winter prep in damp coastal Ireland?

Thanks to anyone with experience with Flow hives getting through winter in damp, mild climates like mine.


  1. What are the most important steps to take for winter prep with a small-but-growing colony in a Flow Hive on the southern coast of Ireland?
  2. Is it better to remove the inspection tray altogether to decrease humidity and diseases that could breed in it, and what would I be risking in removing the inspection tray beyond not being able to see what’s fallen into it?
  3. Can you spot any corrective action I need to take now?


This is my first year minding bees and I have one smallish colony in a 8x Flow brood box. I’m on the southern coast of Ireland where it’s very wet but almost never gets close to or goes below freezing. The colony was established too late in the year to collect honey from and were successfully re-queened. They have been bringing in pollen like crazy (probably just ivy at this point but lots of other species before) and I’ve fed them about 5kg of sugar in total in a 2:1 syrup over the last month in a Ceracell top feeder. There is the occasional wasp trying to gain entry so I’ve reduced the entrance small enough for them to defend, and I’ve watched them drive off many single wasps in recent days, and set up a wasp trap about 5 metres away. I’ve watched the hive grow in number nicely since the new queen, but they still haven’t filled out the outer frames (all of which have foundation). I have done no varroa treatment yet but a nearby beekeeper has promised to loan me two strips of I think Apivar in the coming days, and I have oxalic acid and safety gear on order, and already have the gear to sublimate it for fumigation.


About once a week the inspection tray looks like this:

(ignore the styrofoam in the corner; I replaced that entrance barrier with something better.)

I have two Flow hives (one is spare this year) so I keep flipping in a clean tray with a thin layer of vegetable oil in hopes of catching a parasite. I have never spotted a single, tiny, crab-like varroa mite carcasses in the muck, but I’ve not yet treated the bees for varroa so I don’t know if a single one would have ended up in the tray anyway.

Thank you so much for your experience-based observations and suggestions!

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Hi John, well done for keeping your colony going, and being proactive about winter prep. I’ll try to answer your very good questions from my experience here in the Philadelphia suburbs of Pennsylvania, US where the winters are not quite the same but have some similarities.

  1. Most important steps - I would not hesitate to treat for varroa with oxalic acid immediately. Make sure you’re geared up and I suggest to do a test burn in a safe area outside if your wand is new, to get a more exact time for sublimation. Reduce the OA amount slightly since your colony isn’t filling your box.

It’s almost 100% certain that varroa are present, and that when the bee population reduces for winter, the varroa population will explode. Disease and weakness from these parasites will spell doom before springtime arrives. Rather than an alcohol wash test that will sacrifice bees from your small colony, you can do a sugar roll test prior to treating just to be sure of the varroa level. Plug that into the search bar for details. I defer to others to advise on using Apivar in conjunction with OA.

  1. I have Flow Classics which I’ve modified to have solid bottoms, so I don’t want to suggest something that would be wrong for your system to work properly. I don’t believe you’ll be wanting to use the tray much over the winter though, so I’m curious to hear what others might say about the possibility of putting a piece of solid insulation either in it or in place of it somehow. In addition to wedging a piece of dense/rigid foam in the space under my hives that don’t have feet but sit on a bench, I place another piece of this under the lid, using a shim to create space for it. And, I bungee more pieces to the outside of the hive. Entrance is reduced and a mouse guard is a must for winter here.

Some years ago here we had the privilege of advice from a very experienced beek in Wales, whose posts about roof insulation eventually convinced me to ditch the ‘quilt box’ idea I was trying out at first. Some swear by it, but I find insulating against temp extremes is simpler & very effective in stopping condensation in the hive. You could take a look at @Dee’s posts for more sage advice with added pertinence to your region.

  1. Your top feeder is great for all but the coldest months. Soon the bees won’t be able to take the cold liquid, but since they may still need food you could put a small heap of dry granulated white sugar onto a piece of newspaper placed directly on the top bars inside the box.

It might be better to replace the outer, unbuilt frames with dummy boards for insulating purposes.

About your tray contents I can’t be exactly sure…looks like usual detritus that is pretty mildewy to me.:face_with_monocle:. it might just be happening in the tray since it’s at the lowest/coldest point and amenable to condensation. Good idea fo keep it clear as you mentioned.

That’s all I can think of and I hope others with Flow 2s in similar climates like @chau06 will pop in with more :+1:

I’ll just make some comments. Forgive me if they seem a little disjointed. Temperature is not your problem in winter. The major issue is dampness. With humidity often near 100% in winter it is important to have good insulation on the hive and in particular to ensure that the roof is warmer than the walls. This will ensure that any condensation runs down the walls. If it drops from the roof it can wet the cluster with unfortunate effects.
Ventilation is important and most people use open mesh floors. Do not also provide a ventilation opening at the top as you will only create a chimney effect.
Remember the flow hive is just a different way of extracting honey and you don’t need to extract honey in winter. The common way to insulate the brood box in winter is to place a thick layer of insulation (eg Kingspan) above the brood box and under the roof.
Do you have native Irish black bees? They are hardy and a single brood box is usually regarded as sufficient to overwinter them.
I think it is not a good idea to leave the flow super on the hive over winter. Firstly the ivy will crystallise in the flow super and be difficult to get out . Secondly the colony cluster will move upwards in the hive in winter and there is a real danger that the queen might try to lay in the super before you inspect next spring. If so you will have a mess on your hands.
If you remove the super now they will likely build out the outer frames, especially as the ivy flow seems good this year. There is probably no need to give additional syrup feeding.
You certainly have varroa but i think your plans will be ok. Its a little late to use apiguard now but oxalic acid in december, either dribble or sublimation, is good. i prefer to use Thymol or oxalic or formic acid treatments as there is no danger of resistance developing with them (they are also ‘organic’ if that counts for you). If you use apivar, it is recommended to use a different treatment next year as resistance can develop.
I would wait and see how much stores they collect from the ivy over the next month or so. This should certainly last them until Christmas. At that stage , if they seem light you can give them some fondant, not syrup.
Wasps are definitely a problem and will destroy a weak hive. However your situation as described seems ok. If you place traps near the beehive, make sure that they are non exit types, that the wasps cant escape from them. Otherwise they will simply act as an additional attractant for wasps to bring them to the apiary.


Thank you so much, @Eva and @JimM for your lengthy and detailed advice. They are both full of helpful perspectives.

My breathing protection is on the way, and then I will have all the bits to count mites and fumigate. I bought a “Gas Vap” from the UK that attaches to a butane torch for oxalic acid fumigation so hopefully that will do the job.

I’ve ordered the reducer that is available for the Flow 2+ for my Flow 2, which ought to also keep the mice out? I have a temporary reducer at the moment because there are a few wasps about but the girls seem to be shooing them.

By observation (not DNA), they are the black a.m.m. and I’m thankful of that. I’ve not put on a super yet but hoping to usher them smoothly into 2022 so they’re ready to forage like crazy.

Thanks again for sharing your experience with a newbie!


I think you have solid advice there already… where in Ohio did you live?

The flat part! :grinning: Sorry for being vague but it’s the Internet after all… Have you had your colonies survive Columbus winters? I think they’ve had some crazy stretches of cold in Central Ohio in recent years.

They did fine - all made it through. There’s so much variability in what people do to prepare it seems to boil down to starting the winter strong, varroa management during the late summer and keeping them dry, but not necessarily warm.


I wouldn’t be too sure about that, since the little bleeders can flatten themselves considerably to squeeze in small openings - esp for a big reward. @chau06 do you use these on your FH2?

Just found this gem of a post with some excellent guidance from our old friend Gerald -
the OP apparently didn’t have a mouse guard, but did have an entrance reducer :anguished:

You need a gap of 9mm or less to keep out rodents. Believe me, I have personal scientific knowledge on skull sizing… :blush:


I did not. My FH2 is up on blocks which may help and although I narrow the entrance, I did not make it shorter. I think the FH entrance is too short for an adult mouse but a juvenile could probably get through. A determined rodent would probably also try to chew the entrance larger…

So, maybe I should…


Forgot about your very pertinent research D! Though I doubt it was specific to beehive break-ins :joy:

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I believe the FH2 entrance is 9mm.

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Mice can squeeze through a 6 to 7 mm hole fairly easy and a young one can get down to a 5 mm hole. They are crafty and squishy.

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