It’s the middle of summer, and if your bees aren’t filling the honey super, it’s probably not because they hate plastic or prefer yellow over black foundation. They probably just aren’t finding enough flowers. If you’re fortunate enough to have healthy bees in a localized area of considerable nectar flow, and they’re still not moving up, maybe it’s just too hot outside.
Some time ago, Utah State University conducted a study on the effects of high summer temperatures on honey production in Northern Utah. Researchers measured the difference in honey gained between shaded and unshaded hives. They found that shaded colonies produced 25 more pounds of honey per colony than hives in full sun. Clearly, excessive summer heat can slow your bees down.
Placing your hive in the shade, however, comes at a cost. During winter, hives in full sun will benefit from a greater amount of solar heat. This means the colony won’t have to work as hard to stay warm, preserving fitness and reducing honey intake. Winter sun also helps keep entrances clear of ice and snow, improving ventilation and reducing moisture. A dry hive in winter prevents chilling of the colony and discourages the growth of mold and other pathogens. It seems in selecting a hive location, the beekeeper must choose between greater honey production or higher survivability in winter.
This dilemma was not lost on researchers at USU. They understood that shade is not an option for commercial beekeepers whose hives pollinate wide open fields of alfalfa every summer. So the study also examined the effect of adding an extra super and combs to the hive. The additional space not only increased the motivation of foragers to gather nectar, but also helped the colony cool the hive in two important ways: by increasing the number of empty cells available for evaporating water, and by providing space for hot air to accumulate – much like the attic does in a house. An extra super allowed the bees to work the space beneath it. As a result, the rule of adding a box when bees cover seven or eight frames should only apply to the brood chamber.
So how effective was the extra super at increasing honey production? A colony in full sun, with one more super than required for honey storage, produced 33 more pounds of honey than a shaded colony without an extra super. This is a rare example of being able to have something both ways. You can put your colony in full sun to improve their chances of overwintering successfully, and keep an extra super on the hive for the times your bees are collecting nectar. If your colony does happen to be in the shade, add the extra super anyway. Shaded colonies with an extra super produced the most honey out of all the hive groups studied.