Ornamental grasses are classic autumn stars, and they’re usually combined with other great fall bloomers, such as Joe Pye weeds (Eupatorium spp. and cvs., USDA Hardiness Zones 3–11), black-eyed Susans (Rudbeckia spp. and cvs., Zones 3–11), and sedums (Sedum spp. and cvs., Zones 3–11). These combos are popular for good reasons: They’re simple, stunning, and no-fail. But with a little imagination and a slightly broader palette of plants, you can make your grasses stars all season long. They’ll still come into their own as the days cool, as you’ll see in these combos, but instead of fading into the background for most of the season, they’ll sail through the earlier months of spring and summer as dynamic, productive parts of your garden tableau.
A Large Grass Deserves an Equal Partner
Not many perennials could stand up to the mass and stature of mature, blooming ornamental grasses like these, but tall verbena is up to the task. This perennial acts more like an annual: blooming all season while it waits for its grassy neighbors to catch up. Tall verbena is pleasingly airy, too, which keeps it from being too strong a contrast to the feathery grass blooms.
1. ‘Hameln’ fountain grass (Pennisetum alopecuroides ‘Hameln’, Zones 6–9)
2. Tall verbena (Verbena bonariensis, Zones 7–11)
3. ‘Northwind’ switchgrass (Panicum virgatum ‘Northwind’, Zones 5–9)
4. ‘Itasca’ little bluestem (Schizachyrium scoparium ‘Itasca’, Zones 2–7)
5. ‘Skyracer’ purple moor grass (Molinia caerulea ssp. arundinacea ‘Skyracer’, Zones 5–9)
Conditions: Full sun; moist, well-drained soil
Bronze Sedges Look Autumnal all Season Long
Who says you have to wait until fall to have autumnal colors? Bronze sedges can be even more exciting in the middle of the summer, when you can use them in unexpected color combos or echo their bold colors in nearby hardscaping. Instead of the grass changing as fall approaches, it acts as the constant, while the nearby plantings change.
1. Weeping brown sedge (Carex flagellifera, Zones 7–9)
2. Armenian cranesbill (Geranium psilostemon, Zones 5–8)
3. Japanese painted fern (Athyrium niponicum var. pictum, Zones 5–8)
4. Variegated Japanese iris (Iris ensata ‘Variegata’, Zones 3–9)
Grasses and Perennials Intertwined
When a grass is planted close to a perennial with a contrasting shape, the plants can mingle to create even more visual interest than if they were given their own space. Before the grass blooms, it adds linear form to this combination. When the grass puts forth its fireworks of arching blooms, it’s like a ready-made bouquet that lasts for weeks. As the blossoms of the purple coneflower fade, the remaining seed heads are the picture of fall.
1. ‘Rubinglow’ purple coneflower (Echinacea purpurea ‘Rubinglow’, Zones 3–9)
2. Pheasant grass (Stipa calamagrostis, Zones 7–10)
3. ‘Silver Ghost’ sea holly (Eryngium giganteum ‘Silver Ghost’, Zones 4–9)
4. Purple moor grass (Molinia caerulea cv., Zones 5–9)
5. Sneezeweed (Helenium cv., Zones 4–8)
Create a Cool Ocean Breeze with Blue and White
It’s just a subtle change that makes this grass combo autumnal. Until the blue fescue’s tawny flowering stems emerge in late summer, this grass contributes a beachy feel when combined with fresh and fragrant white heliotrope and sweet alyssum. The nearby pea gravel is dotted with blue sea glass that echoes the hue of the fescue.
1. ‘Elijah Blue’ blue fescue (Festuca glauca ‘Elijah Blue’, Zones 4–8)
2. ‘New Carpet of Snow’ sweet alyssum (Lobularia maritima ‘New Carpet of Snow’, annual)
3. White heliotrope (Heliotropium arborescens ‘Alba’, annual)
Conditions: Full sun; moist, well-drained soil
A Long-Lasting Combo Keeps Giving and Giving
All three plants in this combo bear upright stems of flowers in shades of purple-red, and because all three are long blooming, you’ll be able to enjoy this harmonious scene for months. The salvia flowers first and continues through the season. The purple moor grass blooms from late spring through summer, and the mountain fleeceflower brings the combo to a peak in midsummer. The show continues into fall. This harmonious group of plants melds well not just in color but in texture, as well: No one plant overpowers the others.
1. ‘Paul’ salvia (Salvia splendens ‘Paul’, annual)
2. ‘Firetail’ mountain fleeceflower (Persicaria amplexicaulis ‘Firetail’, Zones 3–8)
3. ‘Skyracer’ purple moor grass (Molinia caerulea ssp. arundinacea ‘Skyracer’, Zones 5–9)
This Unusual Grass goes with Everything
This new cultivar of ornamental rice presents a plethora of combo possibilities with its dark, dramatic, dusky black blades that turn multihued and vibrant in fall. It creates exciting contrasts with almost any color, whether of flower or foliage. Because the plant can mix successfully with deep purple, chartreuse, and silver all at once, it can handle anything you throw at it. The substantial flowers are a bonus, which makes this annual grass a full-season star.
1. ‘Black Madras’ ornamental rice (Oryza sativa ‘Black Madras’, annual)
2. ‘Powis Castle’ wormwood (Artemisia ‘Powis Castle’, Zones 6–9)
3. Sweet potato vines (Ipomoea batatas cvs., Zone 11)
Shape can show you the way
Michelle Gervais is the associate editor
Photos: Michelle Gervais, Jennifer Benner. Illustrations: Martha Garstang Hill, Designed by Barbara Weirich for her garden in Benton Harbor, Michigan, Photo by Danielle Sherry, Designed by the staff of the Berkshire Botanical Garden in Stockbridge, Massachusetts
*This species is considered invasive in some areas. Please visit the website www.invasive.org/weedus/index.html for more information.