Asters and Goldenrods: Ecological Superstars
Across the grounds of Brooklyn Botanic Garden, asters and goldenrods are beginning to shine. You can spot their dainty, mounded, purple-hued blooms and swooping, yellow clusters in the Native Flora Garden, the Shelby White and Leon Levy Water Garden, and the Discovery Garden, on the Robert W. Wilson Overlook, and along Belle’s Brook, the area I tend.
Ecologically minded gardeners love growing goldenrods (
Solidago spp.) and asters (a term we’ll keep using here, though many species native to North America now belong to the genera Symphyotrichum and Eurybia). Both belong to the vast Asteraceae or daisy family .
The New York Times illustrated in a 2020 interview with former BBG gardener Uli Lorimer, this late-summer pairing offers crucial support to native insects, and blooms after many other species have already flowered—providing both beauty and wildlife resources from midsummer all the way into late autumn.
Early goldenrod ( Solidago juncea) in bloom in the Native Flora Garden. Photo by Uli Lorimer.
So, who might you find gracing these distinctive flowers?
Both goldenrods and asters provide sustenance, breeding sites, and overwintering spaces for numerous native species of bumble bees, long- and short-tongued bees, wasps, flies, butterflies, moths, beetles, spiders, and more.
The goldenrod crab spider ( Misumena vatis), seen here on Canada goldenrod ( Solidago canadensis), is an important predator that often hunts among goldenrod flowers. Photo by Uli Lorimer.
Pearl crescent butterflies, for example, draw nectar with their tubular tongues, or proboscises, from a variety of plants, including asters, which offer flower clusters arranged as broad landing spaces. After mating, females lay eggs under the leaves of aster species.
According to pollinator conservationist Heather Holm, gynes (future queen bees)—including those of the endangered
rusty patched bumble bee—consume goldenrod, aster, and other native plant nectar to build fat stores in preparation for their winter hibernation.
A small carpenter bee ( Ceratina sp.) visits a New England aster ( Symphyotrichum novae-angliae). Small carpenter bees overwinter and nest in the stems of asters and goldenrods. Photo by Uli Lorimer.
A bumble bee ( Bombus sp.) and a large milkweed bug ( Oncopeltus fasciatus) visit a downy goldenrod plant ( Solidago puberula). Photo by Uli Lorimer.
Mason bees of the genus
Hoplitis nest and create brood cells in the pithy stems of asters, goldenrods, and other plants, forming partitions by chewing leaves into a paste. And leaf beetles also live on and eat these plants. The young of some species, like the goldenrod leaf miner ( Microrhopala vittata), tunnel into the leaves to eat.
A pink-edged sulphur butterfly ( Colias interior) drinks nectar from a smooth aster plant ( Symphyotrichum laeve). Photo by Uli Lorimer.
Galls, a type of external growth on plants, offer another fascinating interaction worth noting. Moths, flies, and midges form galls with several goldenrod species. The galls are created when eggs are laid on a stem and their larvae enter the plant, creating a swelling where the larvae eat and overwinter—in some cases providing a nutritious snack for birds.
Though some aster and goldenrod species have a reputation for being unruly and competitive, gardeners can keep them in balance by thinning them out or dividing and transplanting when needed.
Many species, like New York aster ( Symphyotrichum novi-belgii) and licorice goldenrod ( Solidago odora), are easy to maintain in a garden.
A “garden ecologist”—as Larry Weaner and Thomas Christopher put it in their book
—will be generously rewarded with a vibrant insect community, whose intricate relations often take place out of human sight. Garden Revolution: How Our Landscapes Can Be a Source of Environmental Change
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Image, top of page: Michael Stewart