Tuesday, October 13, 2015

Winter Preparation for Vancouver Beekeepers

      It's October and there is still a minimal supply of nectar and pollen in our 4 acre garden from primarily the common Asian Aster, Japanese Anemone and Autumn Joy Sedum.  I've identified our foraging shortage to occur in September to October so plan to separate the root balls of the Aster this fall to create more plants. When mature the Aster becomes a 1.5 by 1.5 metre (4 by 4 foot) bush with hundreds of flowers and can bloom well into October.  We have about a hundred autumn flowering variety Asters in our 4 acre garden.  Canada Goldenrod (Solidago canadensis), a native member of the Aster family is also in bloom.  A mixed diet is essential for the girls so I will also be planting other varieties of late blooming plants like Caryopteris 'Dark Knight' (Blue Mist Spirea), Dahlia, Hardy Fushia, Seven Sons flower (Autumn Lilac), Impatiens omeianan, Camellia sinensis (Hardy tea bush) and Osmanthus fragrans (Fragrant Olive) (Nutritional Value of Bee Collected Pollens and Pollen Sources).  I will avoid the temptation to plant the invasive late blooming ivy and Himalayan Balsam. 

     Winter preparation for bee colonies in Vancouver, like the writing of this post should have begun by August 1st or earlier (Beekeeping Calendar for B.C.).  I complete my winter hive setup by the middle of October.  Much of what you do in preparation depends on your management style of beekeeping (virtually nothing for the extreme natural beekeeper to intense management for most commercial beekeepers).  These are just a few suggestions based on my experience keeping bees in Vancouver.
     The biggest problem I see with new beekeepers is not planning ahead.   In our beekeeping coop new beekeepers are always rushing around for needed hive boxes and frames, feeders, robber screens, quilts …. The best advice I could give new beekeepers is to plan 2 months ahead of where you are at.   Pest and disease identification and control should be an ongoing process and if you are beginning now it may be too late.  Evidence of chalk brood or nosema would indicate a weak colony (Honey Bee Diseases and Parasites).  Increased ventilation and removal of old comb can be done to combat the chalk brood and a pollen patty/fumagillin mixture may help combat the nosema.  Mite counts throughout the year and subsequent treatments should let you know whether you have a major issue.  Mite treatments like formic acid can continue into October as long as there is a day time high temp of 10c and oxalic acid is usually done in December when there is little to no brood present.  A reduced screened entrance using eighth inch hardware cloth can be used to allow for needed ventilation during formic acid treatments while providing a more easily defended reduced entrance.  The video below "Getting Your Hives Ready for Winter" is a recorded webinar with Kim Flottum (Bee expert and editor of Bee Culture magazine) which does a very good job of discussing winter preparation for bee colonies focusing on year around mite control.  Controlling mites goes a long way to controlling virus transmission and overall colony health.

      The bee colonies are actively into winter preparation by increased house cleaning, increased hive defense and the removal of drones.  The drones having fulfilled their roles in hive thermoregulation and mating become a liability as they do not participate in foraging or hive tasks and can consume twice that of worker bees.  Hygienic house cleaning (i.e removal of dead bees, applying antiseptic propolis ...) which is difficult in the cold of winter when the bees are confined to the cluster is an important part of disease reduction.  With the decrease in available forage robbing and wasp attacks become a real concern so guard bees will become more defensive and in the wild the colony may reduce the size of the entrance with propolis and wax.  The beekeeper can assist by reducing the entrance to as small as 1.5 centimeters or a half inch to make it easier to defend.  If wasp attacks or robbing persists you can use a robber screen which are easy to make.

      The U.S. Bee Informed Survey (the only large scale North American survey of this type) of wintering hives showed that only 3 conditions determined winter survival success and they were adequate food, strong colonies (equalization) and ventilation.

The survey is extensive and includes the results for geographic region, all types of pest and disease management, feeding and winter preparation.  The Bee Informed Survey 2014 - 2015

Wrapping and insulation showed no benefit but I think that depends on where you live.  If you live in cold northern climates like Winterpeg either you wrap and insulate or you bring the girls inside. 40 below is 40 below.  Insulation is not necessary in Vancouver and can be counter productive by keeping the heat out and preventing the hive from warming up.  Some local beekeepers wrap their hives with black roofing paper to prevent wind penetration and to help absorb the heat (Black objects absorb more heat).   The argument against this is that the girls take care of any wind penetration with use of propolis and do we want a warmer hive in the winter?  Warmer means more active bees and more food consumption.  For us wrapping in March may be an option as we have lots of blossoms (Willow, forsythia, flowering cherry, bulbs ...) but marginal foraging temperatures.  Wrapping would warm the hives and get the girls flying earlier in the day increasing their pollen and nectar intake and stimulate egg laying.

Temperature difference on black and white surface
     Wintering your bees is like real estate value in that the 3 most important considerations are location, location and location.  Location dictates the methods you will use to protect your bees from the elements. Windbreaks are essential in some areas where there are cold, winter winds.  In winter Vancouver has a predominant, low pressure weather pattern with winds from the southeast that bring with it fairly constant cool, wet weather.  We have only a few snow falls per year and a few weeks of freezing temperatures.  Therefore moisture not cold is our biggest issue.  The moisture is created when warm air created by the cluster of bees rises and contacts the cold inner cover creating cold condensation which drips onto the cluster.  There are a lot of different methods to reduce moisture in the hive like tilting the hive forward by putting a 2x4 under the back of the hive to allow the moisture to run down the front of the hive and not on the cluster.  Most of the beekeepers in our coop use an Insulated Moisture Quilt placed above the hive boxes to reduce cold condensation dripping on the winter cluster.
The bee hive in winter without any form of moisture reduction

Insulated Moisture Quilt
The heat produced by the cluster rises to contact the warmer insulated cover producing less condensation, which then drips onto the wood chips (not the bees) which are dried by the vent holes.  They are easy to make out of scrap material and the link above provides detailed building instructions.  During winter you must have an upper entrance in your Langstroth hive for ventilation and because dead bees can block the lower entrance.  I presently have my upper entrance covered with eighth inch hardware cloth to keep out robber bees and wasps.  I will remove this once those threats have passed.  For moisture reduction in a Kenyan Top Bar Hive beekeepers can use an insulated moisture quilt, carpet over the top bars (Bill Stagg's method) or reflective insulation (Sam Comfort's method).  Whether you leave your screened bottom board open or not (for increased ventilation) is debatable but if left open you must block the drafts from blowing under the hive.  I put the mite test board in to block the winter winds but have friends who do not and successfully overwinter their bees.  In Vancouver we get at least 2 major storms a year of 80+ km winds (50 miles per hr).  For this reason we use cinder blocks on our hives to prevent the outer cover from blowing off and have positioned the hives to have a natural wind break (berm to the south).  A wind break is particularly important for roof top beekeepers.  Though not necessary some of us use pieces of plexiglass extending 4+ inches over our outer covers to provide additional weather protection and extend the life of our beekeeping equipment.
 Winter Hive
       Experienced beekeepers will tell new beekeepers it's better to have 2 hives than 1 because inevitably 1 will be stronger than the other and this allows you to strengthen the weaker hive with bees from the stronger (Equalization).  By adding 2-4 frames of bees and brood as needed and available every 3-4 weeks starting in July you can substantially help your weaker colony winter over.  If you find you have a weak colony now in October you can combine the colony with a stronger one removing the weaker queen (equalization).  Some beekeepers (not me) like to requeen as part of their winter preparation to make sure they have young, active queens the following spring.  If you haven't already your Langstroth colonies should be reduced to 2 deep supers and your Kenyan Top Bars reduced by moving your follower board or your false backs forward (Winterizing your Top Bar Hive).  Queen excluders should be removed so the queen can move with the cluster as it moves upward.
      It's good at this point to make sure you have your emergency winter feeders ready. A major cause of colony death is late winter starvation (February - April) which can be solved by the use of an emergency winter feeder (Candy Board). 
They're easy to build with 1x2's and quarter inch wire mesh and can be a colony lifesaver.  You can quickly check on the feeders through the late winter to gauge the status of the food supply.  Because of the drought this summer and subsequent decreased nectar supply our winter food supplies are not what they should be with some of the colonies so some of us have been feeding syrup and pollen patties for the last month.  Some beekeepers begin feeding in August.  Personally I don't feed unless needed and in most years it's not.  This article "Feeding Bees in Winter" describes the different methods of feeding at different temperatures.  The girls will take a 2 to 1 syrup down to about 12 celsius (53 fahrenheit) after which they find it too difficult to process for storage.  Some beekeepers will feed syrup baggies in colder temperatures on the theory that heat from the cluster warms the syrup.  I've not tried this.  In the Greater Vancouver area there are very big differences in winter food requirements based on available foraging days and available forage. Because of the  effect of the North Shore Mountains precipitation varies from 150+ inches (380 centimeters) annually at the upper altitudes of the mountains to 30 inches (75 centimeters) along the U.S. border.  This effect reduces precipitation and increases hours of sunlight as you move southward.  The graph below divides Greater Vancouver into 9 zones with 9 being the upper altitudes of the North Shore Mountains and 1 being the southern region along the U.S. border (Greater Vancouver Precipitation).  As the crow flies this is a distance of less than 30 kilometers or 20 miles.
Though active at lower temperatures I have found high population foraging in our apiary at 12 degrees celsius (53 fahrenheit) in March (Willow trees, Forsythia, Flowering Cherry).

This means more flyable, foraging weather the further south you live and the more active the colony with the additional needed sunshine warming the hive and bees. I have observed the activity of the bees throughout the lower mainland to be directly linked to the number of hours of sunlight on the hives.  Conclusion, for optimum colony health move to a southern suburb like Tsawwassen, Ladner, White Rock or Abbotsford or maximize the sun exposure on your hives (South to southeast exposure with minimal shade).  This is becoming a major issue for us surrounded by fast growing Black Locust, Willow and Cottonwood trees (Great pollen and nectar sources). 
      Also effecting hive performance is available forage which can vary according to whether you are in a rural agricultural or urban setting. The rural, agricultural areas in Surrey, Delta and the Fraser Valley tend to have extreme honey and brood production during crop blossoms but can suffer in the off season while the urban areas tend to have a more consistent food source availability throughout the foraging period (March - November) due to urban landscaping and irrigation. We're fortunate to have 7 cultivated acres in our 2 combined community gardens surrounded by fields of clover with flowering trees.  While it varies by region, because of the reasons discussed above (weather and available forage) and the size of the colony we need on average at least 8 deep or 10 medium frames of honey (65 lbs or 30 kilograms) to over winter.  The honey frames should be positioned on both sides of the cluster in the bottom box and above the cluster in the second super (super = hive box).  If the cluster is in an upper box I like to switch the box to the bottom in preparation for winter.  In the spring you can reverse that process as the girls will have worked their way up to upper part of the second box.
Winter cluster
For a Kenyan Top Bar put the cluster at one end and the honey frames next to the cluster.  I've always run all deep supers in my Langstroth hives because universal boxes and frames are easier to manage.  I can add honey frames from my third or fourth box to the brood boxes to over winter.  Many new beekeepers and some old are moving towards all medium boxes because of the lighter weight.  This makes sense as a deep box of honey can weigh 80 lbs (36 kgs).
      All beekeepers have plus and negative food accumulation months and generally April 1 to Oct 1 are positive food accumulation months for us in the Strathcona area of Vancouver.  March and October can be neutral or negative depending on the available foraging days (weather).  November through February are winter cluster, negative food accumulation months.
      Wasps are a major problem for us in the late summer and fall so we have reduced our entrances to less than an inch and screened off the upper entrances. This blocks potential wasp intrusion and robbing by other bees on the feeding and still allows ventilation. The girls are better able to defend the reduced single entrance.  I don't indiscriminately kill wasps (I've identified 9 different types in our garden including recently a parasitic wasp in my blue mason cocoons) but have found them increasingly aggressive towards our colonies for a longer period of time in the fall (last year until December).  I've found the lure variety to be very effective on our greatest threat which are the common Yellowjacket wasps.  This lure trap can also be used in the spring to kill the emerging wasp queens.  Home Depot sells these locally.

Wasp trap
      Though still mild it's time to think of mice which like to winter in the hives. There are a hundred different varieties of mouse proof entrances from quarter inch screened mesh, drilled metal sheet to simple nails minimizing the entrance.  The mice can get through a fairly small area and will chew through wood.  I use a simple wood entrance reducer with a nail reducing the entrance to just over the width of a bee.  This allows for the removal of dead bees which the girls do as part of winter house cleaning.  If you find the mice chewing on the entrance reducer you can wrap it in wire mesh.

Difficult house cleaning
Wire mesh mouse proof entrance reducer
       For more information on wintering your colonies check out the recorded webinars by Kim Flottum, "Getting your hives ready for winter" or "Putting the hive to bed for winter".  You may also want to check out The Biology and Management of Colonies in Winter , Winterization Guide for Beekeeping , The Thermology of Wintering Honey Bee Colonies or Wrapping a Honey Bee Colony with Tar Paper  from the Beekeepers' Library.  Good luck to you and your bees and stay dry.

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