Much of the knowledge summarized below was informed by these BEE-L discussion threads which occurred in August 2015:
A scientific study of the benefits of feeding sugar water (as opposed to leaving honey) for overwintering in cold climates can be found in: Bailey, L. "The Effect of Acid-Hydrolysed Sucrose on Honeybees". Journal of Apicultural Research Vol.5, Iss.3, 1966, pp.127-136.
I asked about references for the one-box overwintering technique;
based on the responses, it seems that this has not yet been explicitly
studied, despite being in fairly common use (other aspects of
overwintering *have* been studied). One person mentioned (off-list)
receiving a grant to perform a study, so perhaps in the next few
years we'll have better information!
Meanwhile, though, I've now seen lots of useful information, both
on this list, and from my last year's professional beekeepers, who
have now published a small handout for their new clients (not
available on the web for now, unfortuately). So first, thanks to
you all! An extra big thank you to Ari Seppälä, who provided
exactly the kind of information I was looking for, in a way that
made it easily adaptable to my slightly less harsh climate.
Below, I summarize my developing understanding of all this, in the
form of a sort of recipe for myself. Please bear in mind that I'm
a novice beekeeper, so for now a "recipe" (with reasons) is helpful
to me. This isn't intended for the pros, who have much more
knowledge and flexibility than I'll ever have! But I figure that
this might be useful to someone else out there, so I might as well
share. And if I screwed up, more interesting discussion will no
doubt ensue. :-) Thus, I submit it with all appropriate humility.
Please note that the following applies to the Montreal climate
(long cold snowy winters) - I suspect a lot of it will be irrelevant
or just plain wrong for milder climates where the bees aren't locked
into their winter cluster for months on end! Also note: my bees
are Italians, from a locally bred queen. Finally, while I was very
interested to read about different approaches to overwintering, we
had excellent success (well, 1/1 colonies survived, not statistically
significant I know!) with the one-box technique last year despite
an unusually long and cold winter, so what I'm trying to do now is
to replicate it. I'm not, for this year, giving serious consideration
to other methods.
I'm adding a bit of extra information concerning varroa treaments
according to the MAPAQ (provincial government) guidelines, found at:
- http://www.mapaq.gouv.qc.ca/SiteCollectionDocuments/Santeanimale/Reseauapicole/VARROACalendrierdecontrele2014.pdf
- http://www.mapaq.gouv.qc.ca/SiteCollectionDocuments/Santeanimale/Reseauapicole/Varroase%20-%20Grilles_comparatives%20pour%20les%20interventions_juillet2014.pdf
So, here comes the One-Box Overwintering Technique, for cold
climates, with dates appropriate for Montreal, and with additional
notes concerning varroa treatments:
- In late July:
- Harvest honey if possible.
- Check for varroa, and treat if required. Mite-Away Quick
Strips are recommended (if sufficient based on the varroa
count) if you want to avoid removing the honey supers. The
winter bees will begin to emerge in mid-August, and it is
important that they originate from healthy, non-parasitized
brood, hence the late July check and possible treatment.
- In mid-August (at least 3 weeks before "Reduction Day" aka final
honey harvest day):
- Check that every frame in the bottom box has both sides fully
built with comb; if not, swap frames around to make it so.
This will optimize food storage for winter, when we later
feed with sugar syrup.
- Make sure to leave some honey in that box: one cold day
without food can kill a colony, and after Reduction Day, the
only food they have will be in the bottom box.
- Ensure that the queen is in the bottom box, and put a queen
excluder above that box, if this is not already the case.
This gives any brood in the upper boxes a chance to emerge
before Reduction Day.
- In early September: perform a varroa check in order to decide on
the best end-of-season treatment.
- In mid-September: Reduction Day! At this point, the upper boxes
should contain only nectar and capped honey (and possibly pollen).
- (About 48 hours before Reduction Day, place a bee escape
above the bottom box. This is optional, but will reduce
the number of bees you will need to remove from the upper
boxes when you take them off.)
- Remove all but the lowest box. You can remove your excluder
and bee escape as this point too.
- If you need a Fall varroa treatment (in this area we generally
do), apply it now.
- Remove the bees from the boxes and frames you've taken off,
by blowing them, or by shaking or brushing them onto a "ramp"
leading to the front of the hive. The white Apinovar drawer
makes a good ramp. This ramp allows "indoor" bees, who may
never have flown nor left the hive before now, to find their
way safely back. If the colony is large, the bees won't all
fit, and there will be lots of bearding, but at this point
in the season, the summer bees are dying off, so in a couple
of weeks, every worker bee still alive will be back inside.
- You can now extract honey from the removed frames.
- The empty frames should be stored in the cold, to prevent
wax moths. Last year we covered the tops and bottoms of each
box with 1/4" hardware cloth to keep mice out, and put a
solid board on top to keep the snow out, then stored them
outdoors. This is a good time to check for old, dark, wax,
and take those frames out of the rotation.
One week later:
- If you treated with MAQS, remove the spent strips before
beginning to feed. The product instructions recommend
against feeding while treating, and one person (Adam Ritchie)
has reported that feeding while treating not only is ineffective
(bees in single brood often won't go past the strips to reach
a hive-top feeder), but the bees can learn an association
between the feeder and the strips, making them reluctant to
use the feeder even after the strips are removed.
- Install a feeder with 2:1 sugar syrup; over the next few days,
feed about 10 kg of sugar (dry weight). Don't feed more than
that for now, to allow room for the queen to make more winter
bees.
Notes on sugar syrup: 10 kg of sugar with 5 kg (5 liters)
of water makes about 10 liters of syrup, or about 2.5 gallons.
https://en.wikibooks.org/wiki/Beekeeping/Recipes_for_the_Bees
- In mid-October:
- Feed again with 2:1 sugar syrup, again about 10 kg of sugar
(dry weight), or as much as the bees will take. Brood rearing
should be at its lowest point now anyway, so it's okay to
let the bees fill all of the remaining cells with "sugar
honey". By the time brood-rearing restarts in earnest, room
will have been cleared by the bees eating to keep warm.
- This would be a good time to install your mouse guard.
- In late October, insulate the hive. Here's what we did last year:
- Put a thick piece of insulating foam board over the inner
cover, with a tunnel gouged out from the position of the oval
hole to the front of the hive, for ventilation.
- Wrap the hive once with bubble-wrap thermofoil (staple it
on), reaching from a bit below the hive body (but above the
ground), to far enough above the top of the foam board that
we'll be able to:
- Fold the the bubble-wrap over the top (foam board), and seal
it shut with tape.
- Place the top cover over all that, so precipitation will not
fall between the wrapping and the hive body.
- Cut a small slit into the wrapping at the front of the hive,
near the top, just where tunnel in the foam board ends. Now
staple the wrapping to the hive just below the slit; this
allows the material over the slit to form a small "hood" over
the ventilation hole (tunnel end).
- To optimize ventilation from the bottom of the hive, cut the
wrapping so that the hive bottom entrance is free - the
wrapping should form a sort of awning over the mouse guard.
- Remove the Apinovar drawer. You've left some dead air below
the screened bottom board due to the way you installed the
wrapping; this should be sufficient to stop cold winds from
blowing through the hive. However, if your hive is in a
particularly exposed location, it might be better to leave
the drawer in.
- In April:
- Perform a varroa count if you can do it without opening the
hive (e.g. sticky board). Treat if necessary.
- Keep an eye on the hive - if it's too light, feed with 1:1
sugar syrup to avoid starvation. Once the maples and crocuses
are flowering and the bees start foraging in earnest, they
probably won't need to be fed unless there's a late cold snap.
- Unwrap the hive and remove the mouse guard once the danger
of freezing is over.
- In May and later:
- Add a box *under* the hive as soon as there are at least
8 frames of bees; using "white" wax (former honey frames)
helps reduce brood diseases. You now have a brood nest two
boxes tall.
- Add a queen excluder and add supers on top one at a time as
the bees fill them about 75% full.
- Split around May 20 to avoid swarming.
("Recipe" ends!)
This year, we built a slatted bottom board (a shallow box with slats
where frames would be, and a windbreak at the front, per the "usual"
directions found in several places on the web). The bees didn't
object, and they bearded less than last year. I may be projecting,
but I thought the hive entrance traffic patterns seemed a bit less
chaotic during busy times, too. I think I'll leave it on for the
winter, since it will increase the dead air below the hive, which
should improve the insulation without decreasing the ventilation.
We also designed and built a slatted "super shim", combining the
idea of the "super shim" and extra entrance, as seen on Dadant's
web site, with the idea of slats to reduce the amount of burr comb
that would otherwise be built. Our extra entrance is protected
with a little metal hood (a drawer pull, actually, inspired by an
idea from "Building Beehives for Dummies"). So I'm considering
leaving that on as well, and using its extra entrance as the
ventilation hole, but I'm less sure of this; it creates a longer
distance for the bees to travel to a feeder installed near the oval
inner cover hole, in the Fall. Does that matter? I'm not sure.
Does it improve the ventilation pattern and reduce the likelihood
of condensation in the Winter, or does it make things worse? I
have to think about it.
Finally (I sure am verbose today!), a couple of additional issues
came up as I was studying all this. First, some people prefer to
keep their hive sized at one brood box all the time, using an
excluder. The idea is very attractive: a huge hive gets rather
hard to handle in a small suburban back garden! I really don't
need my hive to be all that big, and the bees already make more
honey per year than I'm likely to eat in my entire life. But...
because I'm in the suburbs, swarm prevention is near the top of my
list of priorities, to avoid alienating the neighbours, so I'm
afraid to restrict their space. Should I just make more splits,
and keep the population under control that way?
And: the idea of taking away honey and feeding with sugar syrup
seems just wrong, but I'm told that in our climate, the "sugar
suryp honey" is actually preferable to real nectar honey for
overwintering, because there are fewer indigestible residues, and
thus less risk of dysentry when no cleansing flights are possible
for several consecutive months. I wonder if there are data to back
up that claim. I haven't yet Googled for that - just sorting though
all of the information and coming up with my "recipe" have taken
all afternoon! But if people here know of any studies on that
topic, I'm all ears. Well, eyes.
Thanks again for all the interesting discussion about this!
Anne.