There are four major factors that affect how your hives will survive the winter.
- Population Numbers
- Bees cluster when the temps are below 57 degrees F to maintain warmth, if their numbers are low they cannot maintain enough warmth to survive cold days and nights. The critical factor is population; the more bees, the larger the cluster, the better they can maintain and generate heat. Secondary factors to hive warmth are location: placement in a sunny spot with good wind breaks.
- Fall brood rearing is/was critical to winter population, the bees hatched out in the fall are the ones to keep the hive throughout the winter months. Best practices for good winter survival is to feed in mid Sept – early Nov.
- If you have small weak hives combine them in Nov or Dec. Either lose one queen by putting two hives together or combine them with a double screen to keep both queens and share heat. Kelly Beekeeping offers a great double screen (item No. 60-R).
- Food Supply
- Is the hive heavy? Weight is one of the fastest and easiest ways to check the hive’s resources. Heft the bottom box of the hive with one hand to test weight.
- In general a full deep of bees should have a full medium of honey for winter food.
- If you use pollen patties for winter feeding be aware that they really attract hive beetles, a half or a quarter of a patty is better than a whole one.
- Open feeders away from the hive can be used when we have a spell of weather 60 degrees and up when the foragers can fly to get syrup.
- February is a critical month, early pollen sources in late Jan. encourage the queen to start laying eggs, by late February brood will be hatching; reduced honey reserves and increased numbers may lead to starvation especially if we experience a Feb cold snap.
- Temperatures
- Bees don’t fly in temps less than 57 degrees, they go into a cluster to maintain a nest warmth of 85 degrees (or less when broodless ) to 93 degrees (with brood). If you open a hive on a cool day they lose a lot of heat. Try to inspect when temps are in the 70’s.
- If you have hives that need relocating a cold winter day is a good time to do it.
- Cool temps are great for scraping and cleaning frames and boxes; the beeswax and propolis is brittle and easily comes off when temps are 35 – 50 degrees.
- Mite Load
- Best management practices include varroa control throughout the year.
- Mite testing should be done about 4 times a year; when the hive is dormant, during population increase, at population peak and during population decrease. A varroa mite level of less than 2 mites per 100 bees is desired. The best sampling methods are a powdered sugar roll or alcohol wash on a sample of 100 bees (aprox. ½ cup).
- The most effective products for use during the winter dormant cycle are HopGuard by Mann Lake, oxalic acid vaporizer and the natural control of a broodless cycle.
- The Honey Bee Health Coalition offers an excellent guide to effective Varroa sampling and control in their Tools for Varroa Management guide. http://honeybeehealthcoalition.org/