Boosting Plant Diversity
Diversity is critical to healthy ecosystems. Scientists have learned that landscapes planted with many different plant species are more resistant to pests and diseases and to the effects of climate change. We face all three of those significant challenges in our landscapes. The traditional gardening practice of massing huge swaths of the same species of plant may look dramatic, but from an ecological perspective, it is unwise. Balance is key when massing plants for pollinators, or we lose diversity.
Pollinator Diversity and Plants
Not every pollinator is attracted to or can use the same species of plants. A long-tongued bee can access nectar from a long tubular flower, such as larkspur, but a short-tongued bee cannot. Bees with shorter tongues appreciate more open flowers in a garden, particularly those with small nectaries (where the nectar lies within a flower). Generalist foragers can use a much greater variety of plants than specialist foragers, so plant for both types. Our pollinator gardens should feed many different pollinator species, and that requires having plant diversity.
Photo credit Carolyn Summers
Achieving Plant Sufficiency
There is a counterpoint to planting diversely. To successfully attract pollinators, you must also plant sufficiently, making it easy for pollinators to find the flowers you are offering and to provide enough of that particular resource. Plant sufficiency, or enough floral biomass, is crucial to feeding all of the various pollinators that may visit our landscapes. Remember, if honey bees are nearby, their large colonies require a lot of floral food to survive.
1) Planting pollinator targets
Pollinator targets are groupings of the same species of plant, which allow pollinators to find the nectar and pollen they need easily. The achievable size for each target in your garden will depend on the size of your landscape. In a landscape with plenty of room for many different species, a target of 3 feet square of the same plant species, for every species, may be a reasonable goal. Realistically, not every garden has the room to achieve this goal. There will always be a trade-off between planting diversely and planting sufficiently, so just do the best you can with the space you have.
Photo credit Carolyn Summers
2) Incorporating plant repetition
Plant repetition is a technique that can be used with pollinator targets or as a stand-alone method in a landscape. With this approach, a single plant species is repeated throughout the garden no matter the size of the landscape. A European honey bee might make fifty foraging trips in a day. She will happily find the repeating plants throughout your garden.
Are you bringing flower power to your pollinator garden?
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