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Bumble bee on blue giant hyssop Photo by Julie Weisenhorn |
As a gardener, you can compare an ‘improved’ cultivar to its wild species in your own garden.
Cultivars vs. Natives in Vermont
When Annie White was a PhD graduate student at the University of Vermont, she compared several native species to cultivars. For two years in two locations, she counted all pollinators--her results are summarized below.She counted all insects and grouped them into broad categories. She included all bees, native and otherwise, butterflies, flies, beetles, etc. that were found foraging on the flowers.
The total number of insects is amazing! And what a difference between the New England aster and wild indigo! Some of the cultivars attracted more insects than the species of other flowers.
Below is a list of plant species and respective cultivars researched by White in 2016. The total number of pollinators (bees, butterflies, wasps and flies) are listed after each plant name.
Species: Achillea millefolium, common yarrow -1414*
Cultivar: 'Strawberry Seduction' - 119
Species: Agastache foeniculum, blue giant hyssop - 973*
Cultivar: 'Golden Jubilee' - 566
Species: Asclepias tuberosa, butterfly weed 230 no difference
Cultivar: 'Hello Yellow' - 331
Species: Baptisia australis, wild or blue indigo - 182 *
Cultivar: ‘Twilite' Prairieblues - 78
Species: Echinacea purpurea, purple coneflower - 729
Cultivars: ‘Pink Double Delight’ - 94; ‘Sunrise’ -112; ‘White Swan’ - 404
Species: Helenium autumnale, common sneezeweed - 1,887*
Cultivar: 'Moerheim Beauty' - 222
Species: Monarda fistulosa, wild bergamot - 877 no difference
Cultivar: 'Claire Grace' - 660
Species: Penstemon digitalis, beardtongue - 229 no difference
Cultivar: 'Husker Red' -147
Species: Rudbeckia fulgida var. fulgida, black-eyed Susan - 119 no difference
Cultivar: 'Goldsturm' -120
Species: Symphyotrichum novae-angliae, New England aster - 2,100*
Cultivar: 'Alma Potschke' - 234
Species: Tradescantia ohiensis, spiderwort - 552*
Cultivar: 'Red Grape' - 279
Species: Veronicastrum virginicum. Culver's root - 616
Cultivar: ‘Lavendelturm’ -1,347*
*This plant was significantly better than its paired comparison; four pairs had no significant difference within the pairs.
Today's Research
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Bee favorite Music box mix sunflower Photo by Julie Weisenhorn |
University of Minnesota Horticulture Extension Educator Julie Weisenhorn continues to research this topic using several annual flowers at multiple locations in Minnesota and Wisconsin. This study is funded by the Horst M. Rechelbacher Foundation.
More on Weisenhorn's work:
Flowers for Pollinators blog
U of M Plant Education Group
Growing Landscapes to Help Bees and Pollinators
Resources
For more information:White, A. 2016. Pollinator Gardens. Accessed 10 Jan 2019. https://pollinatorgardens.org
Authors: Mary Meyer, Extension Horticulturist; Julie Weisenhorn, Extension Educator