Pollinators & Winter Habitat Conservation: A New Approach

I’m sure you’ve noticed there are very few insects out and about during the winter, but have you ever wondered where they go? Some conclude their life cycle when temperatures begin to drop but many other insects, including most native pollinators, hibernate during the winter season. Before you clear your yard for winter—please consider the pollinators!
Our native pollinators in Washington State include bees, wasps, flies, moths, butterflies, beetles, bats, and birds (Native Pollinators 2005). Many insect pollinators hibernate during different life stages, including egg, larva, pupa, caterpillar, and adult depending on the species and are dependent upon a variety of undisturbed habitats to hibernate in a safe place through the winter (Attracting Native Pollinators 2011).

What kinds of places do insects and pollinators hibernate in? There are many different niches that are utilized by insects and pollinators including: brush piles; tree stems, bark, cavities, and logs; shrub and flower stems, especially hollow ones; rock piles, wood piles, and bare or undisturbed ground and soil. Insects also utilize leaf litter and man-made structures like house eaves. They seek anything that will provide safety and insulation from cold temperatures and disturbance (Nesting 2020). Around 70% of native bees in the Pacific Northwest nest underground and for many species this includes during their winter development and growth stage before warm season emergence. In cold climates like ours, most butterfly and moth species prefer leaf litter for their eggs, caterpillar, and chrysalises during winter, with many disguising themselves in a pile of leaves (Nesting 2020).

A friendly approach to supporting pollinators year-round is to leave some untidy and undisturbed spaces in your yard from fall through late spring. There are many simple things you can do to minimize disturbance and support our pollinator species throughout winter:

• Create a brush, wood, or rock pile with small gaps throughout in a quiet corner of your yard.
• Prune dead shrubs and flowers back to a taller height rather than ground level, leaving hollow stems for solitary bees to make a home in.
• Rake up less leaves from your lawn or create a pile in a corner of your yard. Use leaves as mulch rather than heavy wood mulch which is hard for insects to navigate through.
• “Plant” an old log in your yard—many insects love an old log sitting on bare soil. Avoid landscaping fabric and plastic or dyed mulches in your yard and instead try using a shallow layer of rock mulch, compost, leaves or just leave some bare soil available.