Thousands of books are written about them, as are poems, and there are even songs sung about the flowers we know as perennials.
They are versatile and can be attractive in the garden as well as in container plantings.
Online articles will often talk about the “10 best,” “15 best,” or “20 best” perennials. These lists often return to the same heralded few, bypassing a whole selection of perennials marked by outstanding qualities.
So, here is a roundup of unsung perennials that deserve a little more love for their outstanding durability, color, form, performance — or all of the above. Let’s give these underappreciated plants their due!
This will be a three-part series. In part I, we’ll talk about groundcovers and other short-statured perennials. Future installments will cover the following:
- Part II: Mid-height perennials and moisture-loving perennials
- Part III: Heat-tolerant, drought-tolerant and tall perennials
Groundcover, short-statured perennials
Allium amplectens (narrowleaf onion), a bulb, thrives in well-drained clay soil, wet winters and springs, and dry summers. In other words, it’s a natural for the Pacific Northwest and higher elevation areas of the West.
“It’s a short-statured, late-blooming showy Allium that looks phenomenal in mass plantings,” said Mike Ridling of Sevenoaks Native Nursery LLC (Albany, Oregon). The flowers bloom May to June in white to pink, on leafless stems, with a height of 6–12 inches.
Aquilegia canadensis ‘Little Lanterns’, a native, is a favorite of Ali Beck, production manager at JRT Nurseries (Aldergrove, BC, Canada) for its very dwarf, barely one-foot-high and wide stature, delicate foliage and red and yellow dangling flowers.
“It looks delicate but is so tough,” Beck said. “I’ve seen them growing out of rocky cliff out of a thimble of soil. It’s not as showy as the bigger ones, and it does self-seed a bit, but very demurely. It’s short-lived, which is advantageous in a self-seeding plant.”
Coreopsis auriculata ‘Elfin Gold’ (dwarf mouse-eared tickseed) is a steady, consistent bloomer of golden yellow rays, producing throughout summer on 8–10-inch-high by 10–12-inch-wide plants with slightly fuzzy deep-green leaves that can turn burgundy in fall. Slow to spread, it is easy to grow and works as an edge plant. Beck recommends it because it is drought tolerant once established.
Cotula ‘Tiffindell Gold’ works as a tough, free-blooming, evergreen lawn substitute that lasts decades, and matures at 2–4 inches high and 24–36 inches wide. Its blooms are like gold buttons. It can be mowed once a year and is virtually maintenance-free, according to Grace Dinsdale of Blooming Nursery (Cornelius, Oregon).
Dianthus alpinus (Alpine pink) is a hardy, rockery carnation, with a tight, semi-flat, low gray mound (2–4 inches high by 6–12 inches wide) and little pink flowers that smell like cinnamon. “It’s old-fashioned, out of the 1950s, and easy,” said Donna Giguere of Giguere Landscape Design (Portland, Oregon).
Dianthus ‘Pink Fire’ is a heavy summer and repeat bloomer on a gray mat, 6–8” high by 8–12” wide, and avoids splitting, as other Dianthus do, said Ben VanderWerf at JRT Nurseries. It is fragrant and drought tolerant.
Many Diascia are sold as annuals, Dinsdale said, but hardier, very drought tolerant ones are worth their perennial status for the mass of flowers — like Diascia integerrima ‘Coral Canyon’, which needs space, but will reward with 4–6-inch-wide plants bearing a mass of soft pink flowers all summer long on 12–13-inch stems. “They’re great in a rock garden,” she said.
Erigeron glaucus (seaside daisy or fleabane) is a coastal evergreen plant that Ridling believes is starting to get utilized by landscape designers for its large, 2-inch lavender-pink blooms with yellow centers, extremely short stature of 2–11 inches high by 12–24 inches wide, fall color and drought tolerance. “It will grow out of a crack with a white daisy that attracts small pollinators,” Giguere said. No watering is necessary for the spring-blooming, fine-textured perennial. Plant it anywhere you want pollinators, she said, as a groundcover under blueberries or apple trees, for instance. “They can get scrappy, but they will stay green all winter if there is no snow.”
Geum coccineum ‘Koi’ bears sprays of orange-red cup-shaped flowers, loose and open on delicate stems, above the 10 inch high by 18 inch wide plant with glossy, “ripply” foliage, almost like lettuce, VanderWerf said. The semi-evergreen mounds do well in the garden and in containers.
Heuchera micrantha (crevice alumroot) is most interesting for its dainty white flower, according to Ridling. It is versatile, surviving in semi-moist to dry applications. Flowers bloom between May and August, depending on elevation, above compact clumps of foliage 1–2 feet wide and reddish stems up to 2 feet high.
Leptinella perpusilla (brass buttons) gets a strong recommendation by Dinsdale to use as a groundcover and in places with light foot traffic.
“I’ve filled a lot of holes with it,” she said, including a long driveway in both partial shade and sun. “It stayed flat,” she said, and the 1 inch high by 12–18 inch wide plant formed a tight mass with no weeds and was maintenance-free. Blooms spring through summer.
Penstemon cardwellii is an easy-to-grow native plant with tubular violet-blue flowers from May to early August, lasting sometimes until fall, that is a pollinator and hummingbird magnet. With small, round evergreen leaves, the 4–12 inch high by 12–15 inches wide plant can be used as a groundcover, in a slab or in a rookery. It roots through nodules on the stem, grows in full sun and needs no water, unless in extreme heat.
“I have seen it die from too much water,” Giguere said.
Sedum spurium “Pink Cloud’ was selected for its hardiness, its ability to withstand heat, dryness, winters — everything, according to VanderWerf.
“When it blooms, it’s a pink could; you can’t see the plant, you can’t see the leaves,” he said. The evergreen forms a vigorous 1-2 inch high by 12-24 inches wide mat.
And Sedum spurium ‘Rhubarb’, with the same growth habit, matches a hot pink flower with a green and red-trimmed emerging leaf for a “stunning” plan,” VanderWerf said. “We’ve been taking it to shows this year, and it got a lot of notice.”
Tiarella ‘Pink Bouquet’ (foam flower) is one of VanderWerf’s favorites with multi-season interest and an alternative to the overused vinca or pachysandra. Clean maple-leaf shaped foliage emerges chocolate and turns green in summer. Masses of sweet-smelling flowers burst open on 12-inch high spikes like New Year’s sparklers and rebloom occurs through August. The leaves are semi-evergreen, and it thrives in sun and shade.
“Viola adunca (early blue violet, sand violet, Western dog violet, and hookedspur violet) forms tight tufts that bloom profusely, and is tough as can be,” Ridling said. A self-spreading native, the white, purple, and deep purple-veined flowers bloom compactly in a variety of conditions, from dry to moist, April through August, on plants approximately 3–6 inches high.
Viola ‘Etain’ (Etain violet) start blooming heavily in spring and keep reblooming, especially in mild winter conditions and even in heat.
“It just keeps going,” VanderWerf said. Yellow flowers trimmed in lavender are large and fragrant hanging above the clump-type 6–8 inches high and wide plants. Although it will survive some heat, it prefers moist soils and part shade.