They’re the stars of the fall garden, the marquee names that never fail to please a crowd. Striking and graceful, billowy and statuesque, ornamental grasses always put in a boffo performance in late summer and fall, when much of the rest of the garden is just coasting toward winter.
“There really is something ‘autumn’ about the grasses-the dramatic ways they move with the wind, the rustling sounds they make,” says Katrina Laflin, a landscape designer and partner in the Batavia landscape architecture firm WehlerPeterson & Associates. With their narrow ribbons of foliage and, for the most part, upright form, grasses seem built to catch every passing breeze and every drop of sunlight.
They’re also well-known for sticking around after the show. Few perennial plants provide so much structure and drama in the winter garden as bunches of ornamental grasses that have faded to assorted shades of beige. Even with a heavy wet snow dumped on top of them, many of the tall grasses manage to look good.
A few grasses peak early. The very popular feather reed grass, a.k.a. Calamagrostis x acutiflora ‘Karl Foerster,’ looks mighty fine from late June on. By now it’s easy to overlook. But most of the grasses we use in Midwestern gardens do their best work during the garden’s third act.
There are, however, too darned many good grasses from which to choose. Not to worry. We’re here to help you winnow down the choices to a few particularly good ones with the help of some local landscape professionals. We asked them to focus on the fall stars, the ones that are ravishing, not merely pretty.
Keep in mind that most of the grasses need a year or more to reach their full stature. They like average, moist but not wet soil, and most want full sun. Plant one now and all you’ll have is an ingenue. Give it time, and it will mature into the grand dame of your fall garden.
Fountain grass (Pennisetum alopecuroides ‘Hameln’ or ‘Little Bunny’): There’s very little that’s showier than a fountain grass, with its profusion of fuzzy flowers spilling out of a shaggy mound of foliage.
Terese Simmons, the perennial buyer at Gethsemane Garden Center in Chicago, recommends the ‘Hameln’ and ‘Little Bunny’ cultivars because both are compact enough for urban yards without sacrificing their showiness. ‘Hameln’ gets 2 feet tall and wide, ‘Little Bunny’ just 12 to 18 inches tall and wide, with slightly more upright flowers.
Little bluestem (Schizachyrium scoparium): Yes, the stems are blue in summer. But if there were any justice, the plant would be named for the fall color of its stems, which go anywhere from rich bronze to brilliant red.
“It’s gorgeous in masses in the fall,” says Rhonda Callahan, retail manager at the Natural Garden nursery in St. Charles. Because it’s not too big–3 to 4 feet high–it’s easy to plant en masse without handing over all the garden space. Traces of the fall red last into winter, giving little bluestem an edge over all those grasses that go beige for winter.
Maiden grass (Miscanthus sinensis): The grass that is easiest to fall in love with, maiden grass has an upright, urn-shaped form and fine foliage that dances in breezes and basks in sunlight better than any other grass. When it sends up its feather-duster blooms in late summer, it becomes positively irresistible.
It’s slightly more tender than native grasses, though, and is often hurt by our most severe winter temperatures if not mulched extra-thick. Even so, maiden grass is a superb choice for fall and winter interest.
Among its varieties, there are some standouts, including Miscanthus sinensis `purpurascens,’ whose foliage lights up in an orange-red for fall, then fades to a deeper hue for winter.
Another preferred variety is Miscanthus sinensis `Silberfeder,’ whose glorious silver plumes stand a few feet above the 5-foot vessel of foliage. Linda Dynek, a designer whose Batavia firm is called Loba Landscapes, likes to pair bold `Silberfeder’ with white pines or other conifers. “Those big seedheads work well with the pines for a strong winter effect,” she says.
For the city gardener, Simmons suggests Miscanthus sinensis `Yaku Jima,’ because it stops at about 3 to 4 feet high. Its reddish flowers stay low, too, puffing out from among the foliage instead of floating above it the way flowers of most maiden grass varieties do.
Northern sea oats (Chasmanthium latifolium): One of the few grasses that prefers to grow in some shade, Northern sea oats departs from the pack of grasses in other ways too. Its straplike foliage 2 feet high gives Northern sea oats the feel of a mini-bamboo plant, a little less graceful and mobile than other grasses.
“It’s a lot more like a typical perennial with that foliage,” Dynek says. And its abundant flat flowers hang down from the stalks, instead of being held aloft. It’s not the instant charmer some grasses are–until fall.
That’s when the dozens of flowers turn a hard copper, along with the foliage, giving the plant a distinctive, almost burnished look. The flowers hang on into winter. If they’re not cut off to be used in a striking dried-flower arrangement, that is.
Prairie dropseed (Sporobolus heterolepis): A primary grass of the prairies, this one shows just how much like a mood ring an ornamental grass can be. A lovely green all summer, it goes golden orange in fall, then sandy brown for winter. It forms a mound about 18 or 20 inches tall, but can take a few years to get there.
The foliage is extra-fine, which prompts Callahan to think of a head of hair when the wind ruffles it. “It’s so pretty, it shimmers in the breeze,” she says. Its short stature and delicate foliage ought to land it a place in the front of a bed, she says, preferably planted in groups of three to five plants to capitalize on its clumping style and its sweet-smelling late-summer flowers.
Very hardy and able to thrive in hot, dry locations, prairie dropseed is a genuine low-maintenance plant.
Switch grass (Panicum virgatum): Another native, switch grass forms an upright clump that can reach 7 feet high, with its airy blooms drifting a bit higher.
Laflin has been smitten with switch grass since her childhod on an Indiana farm. “It’s neat how the blooms look so delicate, but with these little floppy seeds hanging on them,” she says. Backlit by the sun, the blooms can look like a spider web strung above the foliage, with water droplets caught here and there in the web.
Both Laflin and Dynek like the cultivar `Prairie Sky,’ with gray-blue foliage. “It’s very close to a blue spruce in color,” Dynek says. She also likes the rich red variety `Rostrahlnusch.’ These and other switch grasses will go yellow for fall, some of them vibrant and others just yellow.
