Overwintering with screened bottom boards in Florida

[bhough]

Dear Friends,

I've just moved back to Florida from Pennsylvania. I started beekeeping in my backyard three years ago in PA and I purchased two nucs from Dadant in High Springs, FL this spring after I moved back to FL.  I'm using screened bottom boards to help with heat, ventilation and mite control.  Two years ago in PA, I had all three of my hives die due to moisture problems, so I'm sensitive to moisture over the winter. (I did not give any syrup in the fall, there was no extra added moisture in the hive from the beekeeper,...)

My question is whether I can leave the screened bottom boards over the winter in Florida (I live in Tampa) to reduce the risk of too much moisture, or should I put on a bottom board when it starts to get cold? I've got two hives now, one with an opening only the bottom, the other with both a top and bottom opening.

Thanks for you help and experience and any advice you can give,
Bruce

[annette]

I leave the SBB open all winter long out here and we get really cold in December, January and February. Down to the 20-30 at night. So far so good with the bees. The only time I place the bottoms back in is when we get tremendous wind storms. Not too often.

[1of6]

Bhough, I bet you're not going to miss those Pittsburgh winters, waiting to get through the tunnels, sliding down the hills, or wondering if your spring's going to be in April or May...

I think you're going to see some very big differences in your management strategies after that drastic of a move/change in climate.  You'll probably find that you can leave the screen only without the tray/board in year-round.

Hope everything goes well for you.  Let us know what all you find that you need to change in the way of management practices.  What I'd like to learn is how hard it is to control your queen stock down there, or how closely you have to monitor it for AHB traits.  Best of luck.

[AllenF]

I left mine open last 2 years here in North Georgia.

[Finski]

.
There are 2 ways to keep the hive dry during winter:

1) keep it warm = relative moisture concent in and out

2) ventilation.

When the hive consumes 15 kg sugar, it produces 10 litre water via respiration. Like inside your car you respirate and the moisture condensates onto windows of the car if it is cold outside.

The larger the hive room, the easier respiration vapour concensates inside the room.
If the human room is full of people, the rises and respiration vapour makes sitting uncomfortable.

In all cases the proper ventilation is essential.

Bees keep 35C temp in the hive when they have brood. That makes that you need not take care about condensation. The dew point is outside the hive.

In winter without brood cluster temp is 23C and surface temp is lower. When warm moist respiration air meets the cold surface, bottom or wall, the extra moisture condensates.  The nights are the cases when it happens mostly.

***************

What I say : try to seek balance with
1) the room what bees need in winter
2)  the hive shelter to keep the room warmer than outside = relative moisture
3) a proper ventilation
4) use your brains and learn, and don't become mad what you do.

It is easy to follow condensation problem and ventilation

[Finski]

.
What I know about Florida winter ???

We have just now 1/3 of country covered with snow. In south day temp is about 0 -  +5C.
In Florida day temps are now 31C and nights 21C.

When I write this in Helsinki, our  clock is 7:01 morning. In Florida 0:07

In Florida (where there?)
temp is 25C
humidity 88 %
dew point 23 C . So surfaces under 23C temp gather water.

On my beekeeping area
temp is -0,4 C
humidity 100%
dew point -0,4C

In the centre of Helsinki
temp  2,7 °C;
humidity 90 %;
dew point 1,3 °C

[pembroke]

here in Louisville Ky I leave screens open year around. Haven't had trouble yet. As all have said ventilation is the key.pembroke

[fish_stix]

Leave them open! Your bees are only going to cluster on the coldest nights, (20's to 40's), of which, if we have a normal winter, you will only have 8-12 nights. The rest of the "winter" your bees will be out working merrily along, gathering pollen and nectar. Feed a couple gallons of 1:1 and a couple pounds of pollen sub starting on Jan 1 and get them built up for the citrus flow in March. Watch out for years like 2010 though; bad news for spring buildups.  :shock:

[bhough]

Thanks you all very much. Very helpful comments.  I feel confident leaving the screened bottom boards on all year long.
b

[Echium]

Another suggestion....use a screened inner cover as well.  I live near the ocean so there is a lot of moisture here.  Before adding the screened inner cover I would get mold growing on the migratory cover, even with a sbb.  When I changed to the screened cover it solved all my moisture problems.  I think it also helps nectar evaporate faster.  I will never go without one.