Pollinator Pairings May 2022: Green Sweat Bee and Echinacea purpurea

Welcome to the second in a series of features highlighting some of the incredible pollinators that can be found at the Somerville Community Growing Center, as well as the native plants that depend on and coexist with these special species. This series was triggered by a generous gift to provide botanical signage in our Pollinator Garden; check out signs showing up in the Pollinator Garden and around the Center! It also builds on the work of Earthwise Aware engaging volunteers in observations of biodiversity. And we are grateful to the support of Tufts Environmental Studies interns who are assisting with this project.

Everyone’s heard of honeybees, but were you aware that hundreds of species of wild bees play critical roles in our local natural habitats without receiving any of the same attention? One of the most ecologically significant and visually striking of these is the Augochlora pura, known colloquially as the Green Sweat Bee, known as the flying emerald of the sky. Distinguishable thanks to its tiny size and golden-green color the Green Sweat Bee is one of the most ecologically significant of these wild bee species. Prevalent throughout New England, it thrives through its close association with pollinator plants, including the native Eastern Purple Coneflower, or Echinacea purpurea, which is cultivated in the Somerville Community Growing Center and in many other locations throughout the region.

At approximately 3/10 of an inch long, green sweat bees are small but mighty. As larvae, they undergo complete metamorphosis through several stages of development to reach their adult state over a period of about a month. Green sweat bees typically build their nests in the bark of rotting trees, feeding in springtime on the pollen of blossoming maple trees, goldenrod, milkweed, and many other pollinator plants. They serve as important pollinators for squash and a wide variety of other crops, making them fantastic additions to local vegetable gardens as well as pollinator gardens. The female bees perform all the work of gathering food and in autumn, after the green sweat bees mate for the last time that year, the males die and the females build nests in trees and logs to survive the winter and lay their eggs. Females can survive to parent as many as 12 nests of larvae over the course of several years. Throughout the year, Green Sweat Bees also serve as an important source of food for spiders, birds, and other insects, which in turn also play important roles in our local ecosystem.

One of the plants Green Sweat Bees rely on the most as a source of food is the Eastern Purple Coneflower, a striking and significant pollinator plant native across eastern North America. Attracting dozens of insect species as well as butterflies and hummingbirds, the eastern purple cornflower is also visually stunning, quite straightforward to cultivate, and has been associated for a long time with impressive medical benefits. Drooping, narrow, lavender leaves extend in a large circle from spiny, red-orange flowers, giving the eastern purple coneflower its distinctive appearance atop narrow stems that can grow as tall as five feet. It prefers to grow in direct sunlight, but is tolerant of some shade. A perennial pollinator plant, it returns year after year, is quite straightforward to cultivate, but as a result can quickly take over a garden. For centuries, it has been used to create a tea said to have important immunostimulatory and anti-inflammatory properties, especially the alleviation of cold symptoms and an increase in white blood cell counts. Altogether, the eastern purple coneflower is a remarkable pollinator plant that can be seen in the Somerville Community Growing Center, and which everyone can easily plant in their own yard, garden, or flower pot. The Growing Center is supporting the efforts to cultivate and build awareness of pollinator plants and the insects who rely on them, and we highly encourage you to visit and read more about what you can do to help.

“No Mow May” is a ​​growing international movement to help support native bees and other pollinators by allowing flowers to grow in lawn areas in early spring, to support native pollinators while other sources of nectar such as Echniacea are still developing. It is reported that the energy needs of a bumblebee can be met by the nectar from eight dandelion flowers!

In March 2021, after three years of advocacy by Green & Open Somerville, Somerville passed the first-of-its-kind native plant ordinance, requiring that native species be planted on city-owned land. Riparian areas and designated transportation corridors will have 100% native plants. Parks will be a minimum of 75% native, and street trees 50%. Read the ordinance here.. Green & Open Somerville isn’t stopping with the ordinance; it has advocated for corridors of native plant gardens in Somerville, using parks and riparian areas as foundations, and then connecting those larger areas with road medians, street tree wells, roof gardens, and private gardens. Renee Scott, of Green & Open Somerville will be presenting on their efforts at a May 23rd online meeting at 6pm hosted by Mothers Out Front-Healthy Soil Livable Future. Register here.

If you would like to learn more about planting for pollinators, how to reduce pesticide use and/or how to advocate for reform, visit the Resources section of the new website for the MA Pollinator Network. Some good sources of information about native plants, or places to purchase them include Grow Native Massachusetts and the Native Plant Trust- the first native plant conservation organization founded to prevent the destruction of native plants in New England.

Closer to home, Earthwise Aware posts their weekly observations of phenology and insect surveys to iNaturalist here, where you can find photos of plants, animals and insects found in the Growing Center. If you would like to learn more and/or contribute, there are opportunities to volunteer and learn with Earthwise Aware on Tuesday afternoons at the Center or at their other sites. Sign up here to join this critical local citizen science movement!