Like people who can trace their roots to other parts of the world, a look at most of our garden plants reveals they’re “immigrants.” Unfortunately, plants that thrive in moist coastal and Midwestern climates and soils are not always well adapted to semi-arid Colorado.
Rather than try to imitate other areas by growing plants adapted to that climate, the Plant Select® program identifies the best plants for this climate. The program is a cooperative effort of the Denver Botanic gardens, Colorado State University and the region’s green industry. Plants are tested, evaluated and finally, if worthy of Plant Select®, raised by cooperators. The plants are available at local garden centers as soon as possible. Five plants have been promoted in 1997.
Though Silver Sage (Salvia argentea) is noted for its huge, silvery, elephant-ear leaves, it also produces a candelabra-like show of white flowers in early summer. A reliable perennial in our dry climate, this outstanding plant flounders within two years in wet climates.
Turkish Veronica (Veronica liwanensis) has only recently been grown in the United States. One of the few plants with true cobalt-blue flowers, this low ground cover will bloom from April to June with minimal water.
SUNSET® Hyssop (Agastache rupestris) was recently introduced from the high mountains of New Mexico. In the spring, the plant produces tufts of low, silvery leaves. From midsummer to frost, this plant grows stems up to two feet high topped with sunset-orange blooms. The foliage has a powerful aroma.
Carol Mackie Daphne (Daphne x burkwoodii ‘Carol Mackie’) is a particularly vigorous, four-foot shrub with cream-edged, nearly-evergreen leaves. It produces fragrant, pink flowers in the late spring and often into the fall.
Another nearly evergreen plant is Alleghany Viburnum (Viburnum x rhytidophylloides ‘Alleghany’). This tall shrub’s winning characteristics include bright white flower clusters in spring and red berries in the fall.
Plant Select® introductions and recommendations are available at garden centers and nurseries. Additional information on the cultural needs of these and other plants in the program is available at the Plant Select® website, www.plantselect.org.