by Diane Engles, HAS Trustee
As we enter 2020, we are excited about new plant introductions that have been selected to grow well in our mountain climate zones. Plant Select® has introduced seven new garden-worthy perennials this year. Plant Select® is a nonprofit collaboration of Colorado State University, Denver Botanic Gardens and professional horticulturists whose mission is to find and distribute the very best plants for landscapes and gardens from the intermountain region to the high plains and beyond. I’ve listed below these new introductions in alphabetical order by Latin name, with a brief description.
Dwarf Leadplant (Amorpha nana), hardy to Zone 3. This cultivar of a small native shrub sports ferny, bright green foliage and is decorative when not in bloom. In June it produces purple spikes with a sweet honey-like fragrance. As a bonus, it doesn’t require pruning to look good. The common name of lead plant refers to the once-held belief that the plant was an indicator of the presence of lead in the ground. It is a pollinator magnet, attracting bees, butterflies, moths, beetles and other beneficial insects.
Because it is a legume, lead plant can fix nitrogen with the help of a symbiotic soil-dwelling microbe and create its own fertilizer. This advantage keeps it looking green and healthy in poor soils. Once established it takes care of itself in the landscape, requiring little water. Leadplant looks great in mixed xeric plantings with Dwarf Blue Rabbitbrush ( var. nauseoChrysothamnus var. nauseosussus), Butterfly Plant (Asclepias tuberosa), Blanketflower (Gaillardia aristata), and grasses.
Next on the list, with a lovely name is Mongolian Snowflakes (Clematis hexapetala), hardy to Zone 5. Mongolian Snowflakes is not a vining clematis; it forms a mound of foliage about 18 inches tall and up to three feet wide. Its bloom season is from May through the summer creating a mounded snowstorm of 2-inch ivory-colored flowers. This clematis has multi-season interest since the spent flowers give way to shiny, feathery seed puffs that are showy in their own right. Mongolian Snowflakes will adapt to low-water conditions and can be xeric once established. It will also take partial shade as well as full sun. Use it in xeric plantings and rock gardens as well as mixed perennial borders.
Golden Candles (Thermopsis lupinoides), hardy to Zone 3. One of the earliest blooming perennials, Golden Candles is a welcome sight after our long winters. Thick clusters of bright yellow buds emerge and open into golden spires. It will keep blooming into June. Lupine-like foliage persists nicely the rest of the summer adding texture to the garden. Golden Candles can reach two to three feet tall and 20-30 inches in width. It is another garden-worthy member of the pea/bean family from Asia, that adapts well to our climate.
Indigo Blue Dragonhead (Dracocephalum ruyschiana),hardy to Zone 3. This new Plant Select® introduction is easily grown, maturing to a tidy mound 12-16 inches x 10-12 inches. Its needle-like leaves become decorated with fragrant dark blue flowers in early summer. Dragonhead refers to the flower shape which resembles a snapdragon. Indigo Blue Dragonhead will thrive in a dry meadow or rock garden setting and is tolerant of a wide range of soil types. It can tolerate some shade; water needs are low to moderate.
Leprechaun Southernwood (Artemisia abrotanum ‘Leprechaun’),hardy to Zone 4. This compact artemisia forms a dense, symmetrical mound of aromatic, whorled silver-green foliage. Leprechaun will grow in in full sun, part shade, or full shade! It prefers loam or sandy soil. It brings a soft texture to borders and rock gardens. An interesting use recommended by Plant Select® is to plant it as a hedge resembling boxwood in xeric locations.
And finally for this year, green and silver forms of Lamb’s Ears (Stachys lavandulifolia), hardy to Zone 5. Lamb’s Ear is a wildflower from Turkey. Both cultivars will take some shade, and prefer loam or sandy soil. Their water needs are low to moderate and they are deer- and rabbit-resistant.
Pink Cotton Lamb’s Ear (Stachys lavandulifolia – Green Form). This cultivar makes low mats 8-10 inches tall and 12-18 inches wide. Foliage is green, soft, and attractive. In late spring to early summer, flossy clusters of pink trumpets appear which are suggestive of pink cotton candy.
Summer Frost Pink Candy (Stachys lavandulifolia ‘P020S’ – Silver Form) . An elegant, silver sport of Pink Cotton Lamb’s Ear grown primarily for its silver-haired leaves — this selection blooms slightly less vigorously than its parent, Pink Cotton Lamb’s Ear, and is primarily valued for its foliage which bring color and texture to a border or rock garden.
We will try to order all these plants for our Gigantic Plant Sale (May 15-17) depending upon their availability. Watch this newsletter for the plant sale Master List later this spring to check for any of these great plants that catch your interest!
Photo Credits: All photos from Plant Select, except Mongolian Snowflakes which is from Juniper Level Botanic Gardens