Monday, May 16, 2016

Early Spring Pollinators and their Flowers

Bluebells and carpenter bee
© Beatriz Moisset

Many gardeners are developing a new concern for pollinators. They look for ways to help them. Aware that a perfectly manicured, pesticide-laden lawn is not good for pollinators they enthusiastically adopt a scattering of dandelions in the early spring.

This is certainly beneficial to pollinators. However some of the passionate claims that accompany this activity are somewhat exaggerated. It is not true that pollinators “need” dandelions. They would prefer other flowers if they had a chance.

Spicebush in bloom
© Beatriz Moisset
Spicebush and pollinator
© Beatriz Moisset
Before dandelions were introduced from Europe and before lawns became so rampant in our suburbs, early spring pollinators were faced with a smorgasbord of early spring flowers. Here is an incomplete list of the so-called spring ephemerals prevalent where I live, in the Mid-Atlantic region: spring beauty, trout lily, trillium, columbines, rue anemones, Dutchman's britches, bloodroot and bluebells. These and others can still be found in nature areas, although they have become extremely rare in gardens and parks. Perhaps even more important to early spring pollinators are a number of trees and shrubs, such as willows, maples (some, not all of them), serviceberry, sassafras, spicebush, redbud, and a little later, azaleas and dogwoods, just to name a few.

Spring beauty and spring beauty Andrena
© Beatriz Moisset
This assortment of flowering plants offers a rich and diverse diet to newly awakened queen bumble bees, early Andrena bees, and other bees and flies seeking pollen and nectar. Some pollinators are specialists on just one or a limited variety of flowers. The spring beauty Andrena, trout lily Andrena and several willow blossom devotees would look at dandelions in despair, not being able to make any use of them.

Trout lily, frequently visited
by the trout lily Andrena
© Beatriz Moisset
The biotic community described above not only nourishes early-riser pollinators but also provides food and habitat for local wildlife. For instance, the red maple serves as a host plant for more than 100 moth species, willows provide food for several hundred species of moths. In turn, these caterpillars nourish birds and other wildlife. By contrast a lawn with dandelions is an impoverished ecosystem with very limited ecological value, more similar to a refugee camp than to a healthy, lively community.

Azalea and its specialist
the azalea Andrena
© Beatriz Moisset
If the goal is to help pollinators we would reduce the size of the lawn and grow some of the plants mentioned above rather than simply allowing dandelions among the blades of grass.

Bloodroot and Red-necked False Blister Beetle
© Beatriz Moisset
Such a goal is hard to achieve for most gardeners and probably impossible or nearly impossible for many of them. So, reducing the use of pesticides and allowing dandelions, as well as a few other small lawn “weeds,” is a good decision. But anybody seriously committed to protecting, not just pollinators, but entire ecosystems would do well to take a look at other alternatives.

Dandelion visited by a cuckoo bee
© Beatriz Moisset
Dandelion and ants
© Beatriz Moisset

1 comment:

  1. I love checking out different species of flowers to see what kind of insects are using them. Lots of interesting treasures turn up in the process.