Julie O’Donald, lead editor, November 2020
For bumble bees to thrive at least three (3) key needs must be met at the landscape level:
- food (nectar and pollen), from early spring thru to the fall
- shelter, a place to raise her young and for the new queens to overwinter
Shelter may be as simple as maintaining areas where fallen leaves and other debris are not disturbed, leaf mulch or brush piles, neglected clumps of grass, stumps in the landscape, fallen logs, old bird houses, stacked wood or rocks.
Most bumble bee queens overwinter in brush piles or leaf litter.
A favorite nesting site is an abandoned rodent burrow, so those moles add ecological value in so many unforeseen ways!
What is key is to have some part of your landscape that is not tilled, turned or disturbed. Underground burrows are easily impacted by such activities.
In nature, bumblebees are found in prairies and mountain meadows where there is an abundant diversity of native wildflowers. An effective way to invite bumble bees to our gardens can be achieved by planting native flowering shrubs that grow in riparian zones and along forest edges.
The Washington Native Plant Society plant list titled “Water-Wise Gardening with Pollinators” supplies an extensive list of native plants that appeal to native bees. Here is a link to their gardening website.
To see a great example of gardening for pollinators using native plants, visit the Pollinator Meadow in Everett. Reservations required.
Below is a list of native shrubs that are easy to grow and available for purchase at native plant sales. Many other native shrubs, trees and wildflowers will increase diversity that further supports bumble bees.
Flowering dates are provided as an approximate guide to help gardeners create an overlap of flowering plants that will be used by bumble bees. Note that dates may differ by several weeks from year to year and region to region.
As a starting place for your garden, consider the follow plant species:
Early spring: February, March, April
- Arctostaphylos species (varieties of Manzanita)
- Mahonia species (varieties of Oregon Grape)
- Lonicera involucrata (Twinberry, a shrub honeysuckle that attracts bumble bees from April to July)
Mid-season: May, June, July
- Physocarpus capitatus or malvaceus (Ninebark native to the Pacific NW, avoid ornamental eastern sp.)
- Frangula (Rhamnus) californica (Coffeeberry is native to California. Grows in full sun with good drainage. Flowers in June)
- Symphoricarpos species native to the Pacific NW (Snowberry) flowers from mid-spring through August, attracting bumble bees the entire summer!)
- Vaccinium ovatum and parvifolium, (Evergreen and Red huckleberry)
- Ceanothus thrysiflorus (Blueblossom). Mountain and east side native species of Ceanothus can be found.
- Native maples (vine, big leaf, Douglas)
Late: August, September, October
(new queens need to feed before overwintering!)
- Helenium autumnale
(Autumn helenium, seek the species form of this wildflower not cultivars)
- Heterotheca villosa
(Hairy goldenaster, an east-side wildflower that grows well in west-side gardens)
In coastal regions non-natives carry this season with New England Aster, hardy Fuchsia, and Strawberry tree. Plants that flower until frost feed new bumble bee queens and other pollinators until they overwinter.
Please don’t collect native plants in the wild. They often transplant poorly and are likely to die in the process.
In addition to native plant sales, regional native plant nurseries are specialists in selling native plants for habitat.
Support local growers who offer healthy plants that will best adapt to gardens.
Pacific NW Coastal Region Native Plant Nurseries:
Native Plant Nurseries East of the Cascades:
It is also important to think at the local landscape level. Asking your city council or county commissioners to put a priority on native pollinator habitat is very important, and an easy win for your local elected officials to provide.
There are many resources for developing/supporting landscapes beneficial to native pollinators. One such link comes from the Xerces Society: Northwest Meadows Landscapes. There is also a vendor of native seeds for restoration planting based in Warden, WA. Their website is: http://bfinativeseeds.com/forbs.php