Field Day: Overwintering Hives with Liz Huxter
Huxter Farm, Grand Forks, September 28, 2021
Expert beekeeper Liz Huxter of Kettle Valley Queens taught attendees about beekeeping in the Kootenay and Boundary region. This field day focused on important factors and techniques for overwintering hives and nucs which the Huxters have used for over 30 years in their commercial apiary business selling bees and queens.
- Overwintering Hives web resource: North of 60 Beekeeping (Etienne Tardiff)
- Workshop 2018: beekeeping with Pedersen Apiaries
Summary of key points for overwintering hives:
- August 1: Check for disease and Varroa mites (you must enter winter with a disease free hive)
- September: Check for a queen bee (you need a queen!)
- September 15: last feeding (do not provide anymore food to the bees)
- Hive location: store away from wind and frost and use some light insulation around your hive. Liz has a good system for insulating and storing nucs (small hives).
Consider the spring weather when choosing your hive’s location including good sun exposure, dry and access to early season pollen.
Detailed: what Liz has learned so far from her data:
– Enclosure is thermally stable (driven by R-Value), energy balance seems to favour -2 to 10C range (90% of temperature values below cluster and above slatted rack), this is the metabolic rate sweet spot. (95% between -6C and 12C).
– Enclosure is the colony’s primary mode of cold defense – even at -40C enclosure outside Temperature correlates with heat loss calculation R2>0.9 and internal Tmin shows minor relationship with outside temperature which was clearly shown in my analysis of a wooden hive
– Starvation is low risk if keeper ensures adequate honey stores. It is easily accessible throughout winter, consumption is predictable at all temperatures in my setup.
– Bees can quickly heat up interior of hive (volume dependent) due to various known (disturbance, brood rearing) and unknown as described in an earlier post reasons at a minimal energy cost. Therefore, increasing heat output to maintain brood nest will have minimal impact on honey consumption.
– Enclosure effectively reduces cold stress on bees, only lower surface area of hemispherical cluster gets exposed to colder temperatures but much warmer than external temperatures due to heat buoyancy effect and mixing of incoming and outgoing air (only one lower entrance). Energy saving process (like HRVs – Heat Recovery Ventilation systems)
– Based on my CDH (cluster Degree Hours 8C), winter equivalent intensity is reduced by 50-60% of what the bees would have to endure without the insulated enclosure.
– Liz Huxter