Autumn Food for Pollinators, Color Feast for People
Photos courtesy of Illinois Natural History Survey, Michael Jeffords, Sheryl DeVore
Plant experts Sandra Mason and Greg Spyreas agree that goldenrods, those prolific plants that bloom bright yellow in September and October, are unjustly maligned. For example, folks often believe erroneously that goldenrods cause hay fever; but it’s ragweed that does that.
“Goldenrods are excellent perennial plants for gardens,” says Mason, who recently retired as the state master gardener coordinator with the University of Illinois Extension Service (Extension.Illinois.edu). “But it is much more beloved in Europe than in its homeland of North America,” she says.
“Goldenrods are classically North American,” agrees Spyreas, botanist and plant ecologist with the Illinois Natural History Survey (inhs.Illinois.edu). “There are about 100 species worldwide, and 90 are restricted to the United States. We can claim goldenrod as very much our own.” Goldenrods tell the story of the changes in the North American landscape, and species range from extremely common to rare.
About 18 native goldenrod species grow in prairies, woodlands and wetlands in the Chicago region, according to Spyreas. They can be recognized by the yellow flowers often arranged in pyramidal or cone shapes. They range from one to six feet tall. “Most bloom in late summer and into fall. They corner the market on that time. That’s their thing,” Spyreas says.
That’s good for pollinators like bees and butterflies that continue to seek nectar for sustenance even though many other native plant blooms have faded. “Goldenrods take up that late niche in the year when most flowers have lost their mojo,” Spyreas says. “Think about monarch butterflies. Goldenrods are blooming as they are migrating and need nectar.”
Unlike ragweed, also native to the Chicago region, those showy yellow flowers of many species of goldenrod have sticky, heavy pollen that clings to insects which carry the pollen to the next flower, so there’s not much chance the pollen will end up in the noses of hay fever sufferers. However, ragweed relies on wind pollination, so its pollen is light and plentiful, easily released into the air and the noses of humans.
Goldenrods also provide food for wildlife in winter in the form of insect galls. These are lumps or growths on the stems of goldenrod that provide homes for wintering insects. An insect lays eggs on the plant, and when they hatch, the larvae burrow into the plant’s tissues. Birds like woodpeckers and chickadees feast on the larvae by tapping into the plants with their sharp bills.
“If you go out to prairies in the middle of winter, you’ll see birds cracking those open,” says Spyreas. “They learn, if I crack this gall open, I get food.” Galls rarely harm goldenrods.
The most common species in the Chicago region is the Canada goldenrod (Solidago canadensis). “It’s a prairie plant, but it likes disturbed prairies and can outcompete other prairie plants,” Spyreas says.
Canada goldenrod would not be as intrusive if it weren’t for the altered landscape, he says. “We have created an entire universe of disturbed high sunlight soil for Canada goldenrod,” Spyreas explains. “Historically, it was not common to have this disturbed open soil where some species could grow as fast and powerful as they wanted.” In fact, he says Canada goldenrod may have been rare at one time and limited to local areas where floods came through and killed other plants or at bison wallows on the prairie.
Canada goldenrod also spreads through underground rhizomes, as well as seeds, according to Mason, and she doesn’t recommend planting it in gardens. It is considered a generalist, which helps it proliferate in many areas. But some goldenrods are specialists.
For example, Ohio goldenrod (Solidago ohiensis) grows in wetland habitats. Spyreas has seen this species at the dunes lands at Montrose Beach, in Chicago. It grows about two feet tall and likes soils with high calcium content, which the soil along Lake Michigan has. Ohio goldenrod’s leaves are super-smooth and silky. It blooms in September and is touted as being deer resistant.
“Showy goldenrod (Solidago speciosa) is a gorgeous, stunning goldenrod that prefers very dry habitats, and can be found blooming even through October,” Spyreas says. Places to see showy goldenrod include Illinois Beach State Park, in Zion, and Sand Ridge Nature Preserve, a Cook County forest preserve in South Holland.
Swamp goldenrod (Solidago patula) grows in bogs, and its leaves are like sandpaper. “It’s easy to identify it because of that roughness,” Spyreas said.
In recent years, a goldenrod that’s native to the Eastern seaboard has been found growing in the Chicago region. Called seaside goldenrod, (Solidago sempervirens), it historically did not grow in the region, Spyreas says. “But today it’s found in almost any roadside in the Greater Chicago area. If you see a goldenrod in a roadside crack, you’re likely seeing seaside goldenrod. It arrived here from the East Coast, where it travelled along highways and along the coast of the Great Lakes, and found a home on roadsides where salt is spread in winter. The leaves are soft, supple and very smooth. When you feel it, you know it instantly. So far, it hasn’t seemed to outcompete native plants.”
Growing goldenrods is great for gardeners that want blooms in late summer and autumn. “I have a lot of shade, so I plant blue-stemmed goldenrod (Solidago caesia) and zigzag goldenrod (Solidago flexicaulis),” says Spyreas. Both are woodland species.
Showy goldenrod and stiff goldenrod (Solidago rigida) work well in dry, sunny, places, Mason says.
For an online field guide to the goldenrods of the Chicago region, visit FieldGuides.FieldMuseum.org/sites/default/files/rapid-color-guides-pdfs/389_1.pdf
Sheryl DeVore is the author of several books and thousands of articles on nature, the environment and health. She can be reached at [email protected].
Goldenrod Species to Grow
• Showy goldenrod (S. speciosa)
– light shade to full sun
• Blue-stemmed goldenrod (S. caesia)
– prefers shade
• Ohio goldenrod (S. ohioensis)
– wet areas, including moist clay
• Stiff goldenrod (S. rigida)
• Zigzag goldenrod (S. flexicaulis)
– prefers shade
Goldenrod Species to Avoid Growing
• Canada goldenrod (S. canadensis)
• Tall goldenrod (S. altissima)
Sources: Wild Ones, Illinois Natural History Survey