Why asters and goldenrods are vital to pollinators—and a feast for the eyes
Peterborough Examiner – September 5, 2025 – by Drew Monkman
Gaze out over any meadow or country roadside in early September and you’ll see the landscape awash in gold and purple. Goldenrods shimmer in the sunlight alongside smaller numbers of asters—purple, lavender, and white. If you walk up to the plants for a closer look, you’ll notice something else: these flowers are alive with movement. Honeybees, solitary bees, bumblebees, wasps, hover flies, beetles, and butterflies abound. To our wild pollinators, September is not the waning of summer but rather a grand banquet—the last feast before the cold weather ahead. Blooming side by side, goldenrods and asters provide one of nature’s most important—and most striking—late-season displays of colour.
Nature’s September stars
After the profusion of spring and summer wildflowers, only a handful of blossoms catch our attention in fall. Chief among them are the goldenrods and asters. Although goldenrod yellow dominates right now, the violets, mauves and whites of asters will reign supreme by month’s end. Sadly, they are so ubiquitous that we almost take them for granted.
Among the most common species are the sun-loving Canada, grass-leaved and tall goldenrods. Scattered among them are pockets of purple New England asters and white or mauve panicled, calico and heath asters. As their name suggests, asters dazzle with star-like blooms. In shady woodland edges, zig-zag goldenrod holds sway along with blue or lavender large-leaved and heart-leaved asters.
Though very different in appearance, goldenrods and asters share fascinating floral traits. Goldenrod flower heads are made up of dozens of tiny florets, each producing nectar, protein-rich pollen, and its own seed. Their small size is deceptive: a single plant can offer thousands of blossoms, making it an insect magnet. Asters, by contrast, have the classic “daisy-like” look. Each head is actually a composite of two flower types—yellow disk flowers at the centre and colourful ray flowers around the edge—each capable of producing a seed. This combination of beauty, function, and productivity ensures a steady stream of visitors.
Together, goldenrods and asters provide the bulk of late-season nectar and pollen. Without these “keystone” plants – species that play a critical role in maintaining healthy ecosystems – countless insects would struggle to find food at a critical time of year.
Robin Wall Kimmerer, botanist and author of “Braiding Sweetgrass”, captured the beauty of these plants perfectly: “They say that the beauty of the asters and goldenrod lies not only in themselves, but in the relationship between them. The complementary colors, purple and gold, together create a harmony that neither can achieve alone.” If you have never read this classic nature book, I highly recommend it.
A feast for many
Over the past week, I’ve been paying close attention to the Canada goldenrods and New England asters in my own gardens. The variety and abundance of insects they attract is astounding. Not only are they fun to watch, but they provide great photo opportunities. Right now, the goldenrod blossoms are teeming with bumblebees along with smaller numbers of honeybees and “solitary” bees like sweat, carpenter, leafcutter, mining and cellophane bees. The round “baskets”, brimming over with orange pollen, are easily visible on the hind legs of the bees.
Also present in large numbers are hover flies—some looking uncannily like small bees— as well as soldier and longhorn beetles which also feed on pollen and nectar. Yellowjackets, paper wasps, and mason wasps are also plentiful. Although wasps lack the specialized structures for carrying pollen, they do contribute to pollination incidentally. Their presence is an indicator of ecosystem health, as they help control pest populations while also visiting flowers to sip on nectar.
And then there are the monarch butterflies. Our asters are a favourite of these iconic insects which are now fueling up for their extraordinary 4,000-kilometre migration to Mexico. Migrating songbirds like warblers also feed heavily on the insects that congregate on goldenrods and asters.
The hay fever myth
Goldenrod is often unfairly blamed for fall allergies such as hay fever. In reality, its pollen is heavy and sticky, adapted to cling to the bodies of insect visitors rather than drift through the air. The true culprit behind September sneezes is ragweed. Its flowers are small and green, releasing clouds of microscopic pollen grains that are invisible to the eye yet highly allergenic. Ragweed plants, usually knee- to waist-high, have deeply divided, fern-like leaves and produce narrow, spike-like clusters of flowers at their tops. Blending almost invisibly into roadsides, fields, and vacant lots, a single plant can release up to a billion pollen grains in one season.
Climate change and increased CO2 levels (this week at 424.80 parts per million versus 422.74 ppm a year ago) are boosting ragweed growth. Higher CO2 in the atmosphere acts as a fertilizer, and warmer temperatures allow the plant to expand their range and reproduce more vigorously. This results in longer and more intense allergy seasons with higher pollen counts. Pollen density is especially high during the morning hours.
How you can help
Anyone with a yard can contribute to September’s gold and purple banquet. Planting native goldenrods and asters is one of the easiest and most effective ways to support pollinators. New England aster, with its rich purple petals and golden centre, not only lights up the garden, but it is especially attractive to monarchs. It is most beautiful when planted beside showy Canada goldenrod. For more shady areas, try zigzag goldenrod and both heart-leaved and large-leaved asters. These plants, as well as many other aster and goldenrod species, are available at native plant nurseries like Peterborough GreenUp. They can also be judiciously dug up and transplanted.
Next time you pass a field or roadside thick with gold and purple blossoms, pause for a moment. Watch the bees dusted with pollen, the monarchs gliding from bloom to bloom, and the chorus of insect life that hums through the air. What may look like weeds to some is in fact a grand buffet that sustains the lives of countless creatures—and enriches our own lives with colour, movement, and wonder. These plants are an invitation to notice, to appreciate, and perhaps to lend a helping hand by inviting them into your own garden.
