Durable Perennials for the Western Garden and Beyond
The United States is a huge country and includes a tremendous variety of regional ecosystems, each with distinct weather, climate, geology, soil types and elevation differences. There is often a “one size fits all” mindset when it comes to looking for perennials and other plants for our gardens and landscapes. And while there are a handful of perennial plants that have tremendous adaptability such as Daylilies (Hemerocallis), Hostas, Artemisia ‘Powis Castle’ (Sage) and some Old World Salvia (Sage), the smart, long term choice is to find regionally suitable perennials best suited to local growing conditions. And this is a good thing. A difference in regional plant palettes give our gardens and landscapes a sense of place that ties in with the area’s native vegetation and the look of our surroundings.
Plant Select®, a cooperative organization run by Colorado State University Dept. of Horticulture and Denver Botanic Gardens, is a plant introduction program that focuses on finding regionally suitable plants for the Intermountain West and Great Plains (the two primary ecosystems found in Colorado). Since the program was founded in 1996, Plant Select has introduced a tremendous number of outstanding plants, some of which have been grown successfully in other parts of the US as well.
A 2010 Plant Select® winner. A very showy perennial recently introduced from the Caucasus Mountains of western Asia, the plants have beautifully Liatris-like spikes of russet-red flowers in spring. It’s right at home in the xeric garden that thrives in a variety of soils types including clay. Plant it in full sun. A short-lived perennial, mulch it with small gravel mulch (to encourage the plant to re-seed itself) and leave some of the faded flower spikes when flowering is finished to allow the plant to ripen seed.
A 2015 Plant Select® winner, Chumby Silky Rock Jasmine is a wonderful late spring/early summer blooming perennial that flowers with clusters of fragrant pink flower with a yellow eye. This is a tough little plant from high in the Himalayas that likes moderate moisture and most any well-drained soil. The foliage makes furry gray-green rosettes that gently spread with strawberry-like red runners making it a superb groundcover for shady and morning sun (partial sun) locations in the garden.
A 2019 Plant Select® winner. This wonderful orange-flowering Ice Plant was discovered as a hybrid seedling in the Salt Lake City rock garden of John Stireman. Blooming in late spring with large, clear-orange-fading-to-rusty-orange flowers, the plant grows to form a low, tight mat of evergreen foliage. Like all the cold hardy Ice Plants, it should be grown in full sun in sandy to loam or clay-loam soil. While xeric, all Ice Plants like some summer irrigation if the rains are scant.
A 2019 Plant Select® winner and the 2006 High Country Gardens Plant of the Year. Silver Spike grass is an outstanding Old World species from the Alps of Europe grown for its very showy late spring display of silver-green flowering plumes. The seed heads age to tawny brown and hold on the plant into the fall. This xeric (waterwise) species is a cool season grower that is best grown in the Intermountain West where the summers aren’t too hot and humid and nights are cool. Introduced into cultivation in the US by Lauren Springer Ogden.
A native shrub from the southwestern US, Littleleaf Mountain Mahogany (Cercocarpus intricatus) features attractive silvery evergreen foliage for year-round interest and bird habitat. Its compact size and outstanding durability make it an excellent choice for hedging and xeric landscaping. In mid-spring, the shrub is covered in plumes of tiny pale flowers, which are pollinated by small native bees to create feathery seed tails that catch the afternoon light.
A super cold hardy Old World native, Golden Candles (Thermopsis lupinoides) blooms with stunning bright yellow lupine-like flower spikes in mid-spring. It pairs beautifully with mid-spring daffodils and tulips, and after flowers fade, attractive foliage mounds will enhance your garden through summer. Easily grown and long-lived, Golden Candles delivers welcome early-season color after a long, cold winter. A 2020 Plant Select® Winner.
A shrub clematis, Mongolian Snowflakes (Clematis hexapetala) blossoms into a cloud of 2-inch ivory colored flowers beginning in late spring. After months of flowering, showy, shiny, feathery seed clusters continue the show, revealing dark green mounding foliage. Remarkably easy to grow and drought tolerant, it is a must-have perennial.
Dwarf Leadplant (Amorpha nana) is a wonderfully compact native shrub that covers itself with purple flower clusters in late spring. Sweet honey-scented flowers attract bees, butterflies, and other pollinators. A member of the legume family, Leadplant adds nitrogen to the soil, helping it thrive in poor soils and benefiting of all the plants surrounding it. Suitable for the most challenging sunny sites. A 2020 Plant Select® Winner