How should I prepare a pollinator garden for winter?
Written by
Kiana Okafor
Reviewed by
Prof. Martin Thorne, Ph.D.Winterizing your pollinator garden takes some strategic habitat conservation. Leave seed heads and stems to give insects added shelter during the cold months. Avoid winterizing your garden until spring to protect overwintering larvae and queen bumblebees. I have witnessed these practices increase the number of pollinators I have in the following year.
Habitat Preservation
- Standing stems: Hollow stalks shelter chrysalises and overwintering insects
- Leaf litter: Provides insulation for ground-nesting bees
- Seed heads: Offer vital bird food through winter scarcity
Mulching Techniques
- Timing: Apply after ground freezes to prevent rodent nesting
- Material: Use straw or shredded leaves, not heavy wood chips
- Depth: 2-3 inches around perennial bases for root insulation
Insect Protection
- Queen bumblebees: Hibernate underground in north-facing slopes
- Butterfly larvae: Overwinter in leaf litter as chrysalises
- Native bees: 70% nest in soil needing undisturbed ground
Use insulating mulch properly for optimal protection. Apply mulch to the base of perennials only when the soil temperature is below 40°F. Use light materials such as straw that support aeration. I do not use heavy mulches that may keep moisture against the crown of the plant, which can lead to rot and/or affect soil temperature.
Establish undisturbed zones for ground-nesting insects. With caution, conveniently mark your queen bumblebee hibernation spots. Ensure that the soil in these areas remains loose throughout the entire winter. My yard has protected areas where leaves collect naturally. These turned into refuges for overwintering pollinators.
Manage water drainage throughout freeze-thaw cycles. Water needs to drain underneath the plant so that the roots don't succumb to ice. Downspouts can't lead to valleys in your bed to collect water. I install simple French drains in problem areas. Good drainage helps protect roots from frost heaves.
Safeguard your container garden with techniques specific to protecting containers. Storing pots next to sheltered walls will reduce wind. Wrap your containers in bubble wrap or burlap for added protection. I like to elevate pots on pot feet to prevent ice from forming between the pot and the patio. These things will keep your root systems alive throughout the winter.
Schedule spring cleanup accurately for habitat preservation. Wait until daytime temperatures are consistently at 50°F before removing debris. Open up parts of a bed instead of doing the whole bed at once. I wait to see when the first queen bumblebees emerge before proceeding with my cleanup. This helps keep an active hibernator from being disturbed.
Read the full article: 10 Best Flowers for Pollinators
