Thetford Center pollinator garden a success — plant it and they will come
All the effort of cutting and rolling up the turf, the layering of newspaper and spreading of several inches of wood chip mulch to kill the grass had paid off handsomely.
Buzzing bees, a lot of them, greet August visitors to the Community Garden on the Thetford Center green. But many of the bees are not buzzing within the fence that shields treasured vegetable crops from deer. The vegetable plot is surrounded on two sides by a wide swath of flowerbed populated with big clumps of mostly white-flowered plants that are unfamiliar to many gardeners, at least those who choose their flowers at garden centers.
This is a pollinator garden, designed by Alicia Houk and installed in 2022 by volunteers, mostly from the Thetford Conservation Commission, of which Alicia is a member. Alicia holds a Master’s Degree in Biology with a focus on pollination ecology. She teaches environmental science and has designed and installed native pollinator and bird gardens in public spaces for the past nine years.
One incentive for installing these gardens is the dramatic decline in bird and insect populations. The number of North American birds has diminished by 30% since 1970, with even common species like sparrows and blackbirds in decline. There are many man-made factors involved here — habitat loss, climate change, cat predation, and agricultural pesticides used on a massive scale all contribute. For instance, sparrows exposed to neurotoxic neonicotenoid pesticides foraged less and did not accumulate as much fat to fuel their migration..
The loss of a critical food — insects — plays a very important part in bird declines.
Insects, spiders, and other bugs are a critical part of the diets of many birds. These small invertebrates are full of remarkable nutrients, providing birds with protein-dense, high-energy food. Some birds, such as warblers, flycatchers, swallows, and swifts, feed on insects for most of their lives. But many other birds that we might not think of as insect-eaters rely on insects during migration and at other important stages in their lifecycle, in particular for raising their young before they are able to fly.
A host of research studies draw the same conclusion — A 2020 meta-analysis found that globally, terrestrial insects appear to be declining in abundance at about 9% per decade. Another meta-analysis of 16 studies showed an average decline of 45% in just the last 40 years. Amid deforestation, pesticide use, artificial light pollution, and climate change, once-abundant insects are struggling — along with the crops, flowers, birds, and other animals that rely on them to survive.
Alicia, from her knowledge of pollinators, notes that five of Vermont’s 17 bumblebee species have disappeared, and roughly 30% of wild bee species are considered imperiled.
Love blueberries? You may be interested to learn that "While commercial growers may use Honey Bees to pollinate their crops, there are several species of native bees that are much more efficient blueberry pollinators.” Bumblebees are also the only effective method for pollinating tomatoes, peppers, and cranberries due to their unique "buzz pollination" behavior, where a bee anchors herself by her jaws and vibrates her wing muscles to shake the pollen from the flower.
Indeed, the pollinator garden on the Thetford Center green was alive with bumblebees.
Alicia had chosen to cultivate a native plant known as slender mountain mint that had expanded into hefty clumps loaded with heads of small white flowers with bees scrambling all over them. Another clustering white-flowered plant, boneset, was full of buds, waiting to unfurl in their turn. Nearby a delicate blue butterfly perched on the purple flowers of hoary vervain.
Lavender-pink wild bee balm had attracted bees, a skipper butterfly, and a spectacular hummingbird clearwing hawk moth, one of the minority of moths that fly by day. It really does resemble a hummingbird, complete with a fan-shaped tail. Its caterpillars feed on honeysuckle, snowberry, hawthorns, cherries, plums, and European cranberry bush. Milkweed was attracting bumble and honey bees but, sadly, only one Monarch butterfly.
The striking pink, leaf-like bracts of spotted bee balm outshone its shy, creamy flowers, while a towering sweet Joe-Pye weed was not quite in bloom. And there were others not in flower whose leaves and form added texture and interest to the mix.
All the effort of cutting and rolling up the turf, the layering of newspaper and spreading of several inches of wood chip mulch to kill the grass — as advised in Alicia's "quick start guide" to a pollinator garden — had paid off handsomely. Apart from the mat of wild strawberries that somehow found their way there, weeds are largely absent. And no watering or fertilizer needed! In fact fertilizing is detrimental to native plants, producing overly lush foliage and top-heavy stems that flop over.
The National Wildlife Federation reported that in 2019, 9% of Americans (about 23 million people) converted part of their lawn to a natural plant/wildflower landscape, and the trend has grown since then. Alicia, our resident expert on the subject, will be glad to help those whose interest has been piqued.