Mother Nature has a habit of making things messy. That’s just how she likes it—nature is just controlled chaos operating under its own system of checks and balances. It’s perfect bee habitat. But when humans disturb that balance—or worse, try to create order from that careful chaos—it can be harmful to the wildlife that depends on it.
Many species depend on nature’s clutter in the cold months, including native bee species!
Clearing our gardens for winter may make our yards look tidy, but leaving it as is can provide important winter bee habitat for our vital pollinators.
As summer fades to fall, the bumblebee queen turns her attention to the coming winter. After mating near the end of summer, the queen stocks up on pollen and nectar, building up her fat and filling her honey stomach. This should be enough to get her through the winter—but she needs to find bee habitat with a suitable burrow in which to hibernate.
Though bumblebees are a social species, the bumblebee queen hibernates alone. Bumblebees nest and hibernate underground, preferring to dig in vegetation and loose soil, so the location they choose is paramount. It must be somewhat protected, and never in a place that could be warmed by the winter sun. This is to prevent premature emergence.
By leaving a layer of leaf litter, you are providing a protected and shaded burrow for the bumblebee queen, giving her the perfect place in which to wait out the winter.
A hollow stalk may not seem like prime real estate to us, but to a mason bee it’s a cozy winter home. Mason bees are cavity nesting bees (which is why they sometimes set up shop in inconvenient human structures). After mating, the female mason bee creates partitioned brood cells in her chosen residence, using mud to separate the cells. The female lays an egg in each of these cells, making sure to leave enough pollen and nectar for the hungry larva that will soon develop. After the eggs hatch, the larva consumes the food mass left for it by its mother, and, once finished, spins a cocoon around itself in which it will morph into an adult. By September, the transformation is complete and the adult mason bees remain in their cocoons, dormant until the last vestiges of winter have melted away from their bee habitat.
Leaving hollow stems in your yard may not be the prettiest way to prepare your bee habitat for winter, but it’s a great way to make sure the mason bees have the resources they need to survive the cold season!
Carpenter bees are aptly named. Their most notable characteristic is their nesting technique: drilling tunnels into old wood. These bees are prolific woodworkers, creating tunnel systems with various chambers which run with the grain of the wood. It is in these chambers that the carpenter bee females lay their eggs. Much like mason bees, this species creates partitioned brood cells in which eggs are laid and provided with pollen and nectar.
Adult carpenter bees emerge in late summer, but as winter nears, they find abandoned tunnels and hunker down to wait out the cold. Carpenter bees prefer bare, unpainted, or weathered softwoods, and are especially fond of redwoods, cedar, cypress, and pine. These bees are considered pests to some homeowners due to their tendency to nest in eaves, siding, or decks.
Create bee habitat by leaving rotting tree stumps or logs in your yard is an enticing alternative for these bees, and may even help your local bee population thrive.
Winter can be fatal to a honey bee hive. These bees rely on heat to get them through the winter, migrating to the top of the hive to the honey stores and balling up in a cluster around the queen, keeping each other warm solely with body heat. Diseases and pests, notably the Varroa Destructor (Varroa mite), can cause disastrous die-off in winter, and may even kill a hive; but these are not the only dangers to a winter hive. Wind can pull that vital heat away from the hive and potentially endanger the bees inside. A windbreak can easily combat this issue and help your bees in winter; these windbreaks can be made out of a variety of materials, but brush or bushes are a perfect natural wind shield in your bee habitat.
By leaving your bushes untrimmed for winter, you’re protecting your hive from wind stress, and improving its chances of survival.