A lot of mails about winterig in north

I live in Central Finland about 62 N  about as north as Joe In Alaska, but 
climate is milder. Coldest ever only -36C. Normal cold weeks  -20 -30 C. Snow 
on the ground November-end of April.

Sometimes a difficult place to run bees, but excellent place to get wintering 
experience:) 

ESP hives have been here for more than 20 years. Now they are a standard in 
beekeeping. Only old timers and organic beekeepers use wooden boxes.
ESP winters well but they should have the net bottoms that are designed for 
them. ESP top stops the air flow up. Moist air from cluster raises up, moves 
sideways and condensates on the sides of the hive. When cold ( about more than 
-10C) ,  condensated water freezes on side frames and walls. On first warm 
spring day a hive can loose 1-2 kg of weight when the ice melts and runs out of 
hive. No problem for bees because no condensation on top of cluster.

Traditional wooden boxes for winter are with double walls and insulation 
between them. Thickness about 5 cm. These are wintered with wooden bottoms. 
Entrance fully open, only with mice net.  According to a study 10 years back, 
the smaller the entrance, the more winter losses. 

On top of hive most common now 3 pieces of 1 cm wood fiber boards. + metal 
roof with wooden rim under it. In these hives the moist air raises from cluster 
and moisture goes through the boards and exits from under the metal roof. In 
place of boards an arrangement plywood with 15 cm hole + glass wool on top of 
it works too. But most beekeepers don?t like this material because of mice 
problems and because it is not hygienic.

A big difference to states and Canada is that no one uses top entrances 
here. 

What is important, is that you can not mix these two types of wintering 
arrangements. With nor air flow up and warm ESP top, you should have net 
bottom. A wooden bottom in this system ends up with thick ice and easily 
suffocated bees. 

Indoor wintering is common, but only a fraction of all hives winter indoors, 
maybe 2 % 

I put all weak colonies and the ones without enough food inside. Normal winter 
cluster in -5C should be on 6 frames or more. If the colony is smaller I take 
it inside. Outside I would loose 30- 60 % of these small ones.  I feed starving 
ones with frames from other hives.  Indoors the losses are as small as from 
normal colonies outside, about 10 %. Wintering normal colonies indoors is not 
profitable if work costs are calculated. 

I winter bees in cellar under my packing house. At the moment I have about 400 
colonies inside and they help a lot on heating bill of the packing place, 
keeping it on + 2C without extra heating. Outside is at the moment -24C.

I ended up putting more hives inside than I wished. All Northern Europe had a 
rainy summer. My honeycrop was 20 kg , 50 % of normal, my new colonies 
developed poorly and ended up indoors.

Ari Seppälä
Finland

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm