Wrapping your beehives for winter means a lot of different things to different beekeepers. Some beekeepers simply use insulated lids and tar paper tacked on to the side of the hive, while others will have heavy insulated wraps and pillow tops, but the consistent design allows for a top entrance for bee flight and ventilation.
Increasing research is finding and bottom board insulation plays an important role in supporting colonies in maintaining a 5 – 7°C temperature. There are many designs that can be emulated, including custom built pallets, and bottom boards. Not much is needed in the way of insulation, and many times success is found by drifting snow or wraps that go down to the bottom of the hive.
Placing rigid insulation below the hive stand or bottom board footings can increase success and fulfill the goal. Decreasing your entrance using an entrance reducer not only reduces the risks of mice moving in, it also decreases the amount of cool air pouring into the hive as a vacuum is produced by the moving convection within the hive. Bottom ventilation throughout the winter months is not even necessity, and a beehive can be placed on an insulated bottom board with no entrance in use.
The risks of restricting the bottom entrance is not because of ventilation but rather the ability of the colony to clean the large number of bees that accumulate as the hive populations natural attrition. The debris will freeze, ferment, and release water and carbon dioxide. This can be detrimental to a hives success. So, if a solid bottom board without an entrance or exit is going to be used, then it is important that the entrance is blocked at the latest possible time, late in to November – December. When the bottom board can be cleaned on warmer days of late Fall – early winter, when the largest numbers of bee mortality take place.
When considering wrapping the hive body, whether a single or a double or a top bar hive, it is important that you recall the insulative nature of the honey stores. Insulating the body of the hive should offer windbreak as well as offer room for ventilation. If your winter wrap is going to choke the hive and the top entrance, then the product is faulty or applied wrong. There should remain a 0% risk of having entrances covered by shifting wraps.
A common option for winter wraps are Bee Cozy jackets made of plastic and are pinned to the hive, using wooden framing around the top entrance. This product is useful, but because of the screwing and pinning of the product to the hive, the holes are bound to allow water to pool within the wraps, causing their insulate nature to be at fault.
Using tar paper to absorb heat into the hive is effective, as well as a rigid insulation sleeve that sits 1/4″ larger than the hive body, offering a dead air space between the hive for insulation and ventilation of the hive is very effective.
The key thing to keep in mind when wrapping the perimeter of the colony is that too much can be a problem. Straw bales (mouse lures) and layers of insulation that make removing and reapplying in the spring can cause problems for bees entering and exiting, as well as efficient management throughout the shoulder seasons. Keep it simple and easy to apply, remove, and stay intact once applied to the colony.
As mentioned repeatedly, hive top insulation should be your focus when deciding how to winter your colonies. Just like in your home, the best way to increase energy efficiency is to insulate and ventilate the attic, so it is the same with your beehive. The better the hive top insulation and ventilation, the easier it will be for the bees to maintain that 5 – 7°C temperature, regulate food consumption and decrease the rate of cleansing flights throughout the winter.
It can be concerning to leave a top entrance visible to the naked eye, especially when you watch that cold front rolling in. Fear not. If your hive top is insulated properly, the heat will work as a buffer. Rather than cold air rolling in to the hive, the heat will move out of the hive. Allowing for a telescoping lid, or a type of awning can create a greater space for buffering of the movement of heat, but is not necessary. The greater the insulation in the top of the hive, the greater the space contained in the hive with a consistent temperature and humidity. Imaging heat as a bubble surrounding the cluster of bees. The greater the bubble, the more room for external environmental temperature changes and the greater capacity of the colony to maintain a mean temperature.
More commonly found in Warre beehives, these are built to work as the attic of a house works. It is a dummy box set above the cluster with a cotton fabric stapled to the bottom, keeping the bees from moving up. The bees are able to fly through the top entrance created by the box or inner cover left on the hive, but the moisture chimney’s through the fabric or through the feeder hole in the inner cover. As the moisture wicks up in to the dummy box, it comes into contact with a dead air space created by wood shavings, rock wool or dense fabric. The extra space that has very little air flow offers insulation and a space, for moisture to evacuate the main hive and away from the cluster. It is a very effective method of wintering.
Wicking moisture away from the cluster can be done in a lot of ways. Commonly beekeepers will tip a beehive forward by 5 degrees, to allow any condensation to bead toward the front entrance and away from the cluster. Using 3 layers of insulation above the cluster, and having one of those layers moisture absorbing is ideal. This can be carpet, weave side down, or silica beads in a permeable membrane, or simply fabric above the cluster between the inner cover.
Above this, rigid insulation, a rock wool pillow layer, or even a custom built insulated telescoping lid work great. The key factor, repeated again, is insulation, moisture wicking, and ventilation. If you can come up with a design to your liking that take in to consideration, you’ll have a winning design.
Are you ready to go more in depth with these topics? Our Level One Beekeeping Course is the perfect opportunity to engage with beekeeping on another level. This course has limited seats so make sure to sign up so that we can notify you when registration is open.