Fall and Winter Preparation
Wintering Risks in "very" cold climates
Diseases and Pest
Managing your Varroa mites will be your main concern to overwintering successfully. Varroa carry many viruses that will impact your colony health but most importantly they will feed on your larvaes and bees Fat Body organ.
The other common disease is Nosema Ceranae. Nosema is a microsporidian fungal infection of the lower bee gut. It is known to reduce the bee's life span, increases honey consumption in winter, reduces the bees productivity and makes them more susceptible to other "chemicals". It has been associated to CCD - Colony Collapse Disorder. Link to a more detailed Nosema discussion.
Treatment options are available for both these issues. However the key is to identify the problem before it gets too serious.
Starvation Basics (2 Types)
There are 2 types of starvation 1) running out of food and 2) cold starvation (bees can't reach honey because they are too tightly clustered to move to it). Both of these are mitigated/eliminated when the hive is well insulated and an effective winter prep is done. I go through my basic approach below.
Note: I have never had a hive starve that was well prepared for the winter. I like making sure the hive has about 100lbs of stores (all in weight - 125 to 150lbs). My hives usually have 2-4 frames of honey left over in late March which is then used to start brood rearing (March to April). I well insulated hive will consume a lot less honey than a poorly insulated one. However I have noticed that wintering hives with Nosema C will consume higher amounts of honey than a healthy one. Also a larger cluster will consume less honey than a medium size one.
My 12 Step Winter Prep Approach:
1. Insert Bee escape and pull honey (not much surplus this year but my top brood box is in the 75-100 lb range - I can hardly lift alone)
2. Remove one empty frame per deep Usually bees ignore outside frames
3. (NEW) Insert new 2 1x10 frame blank per deep (help with moisture and remove empty space where bees usually get wet in winter during warm spells followed by cold spells - condensation)
4. Treat each hive with Nozevit+ (certified organic Nosema treatment (NEW)) / Fumagilin B can also be used.
5. Feed 4 L of 2:1 syrup (more if they go through it quickly)
6. Feed pollen patty (Early August or late July based on available natural pollen)
7. Treat OAV for varroa (1st year hives) - I now treat in spring if required and monitor mite levels regularly (monthly)
When cold sets in: (remove any pollen patty left in the hive)
8. Put extra medium on top to hold combined moisture quilt and dry sugar cake/ 2 x R10 Insulation. New setup will let me easily add pollen patty and baggy feed bags in spring. I'll put a piece of styro above feed area to prevent heat loss. Still debating top entrance or no top entrance. I have had better success without.
9. Bring hives off the stand onto 2" styro and ~2 pallets (or when I get a strong helping hand)
10. Bubble wrap 2 hives together (or 2" styrofoam + bubble wrap for wood hives)
11. Protect front entrance from snow and wind (use piece of plywood)
12. Ignore them until March...
Quebec Bee Escape
Bee escape placed between honey super and main hive bodies overnight
OAV mite treatment
Bee gobbling down a pollen patty / 2:1 sugar syrup is also being fed to hive to backfill shrinking brood nest
Prepping my candy board and moisture quilt
installing sugar board / adding wood shavings to 2 compartments
Hives placed together to share heat and reduce exposure