Many gardeners turn to perennial plants to add color and interest to the landscape. Colorado lies within United States Department of Agriculture (USDA) Hardiness Zones 2 to 7. Colorado gardeners should choose perennials according to appropriate zone, culture requirements, bloom time and mature size. Various perennial landscape plants thrive in Colorado gardens.
Colorado columbine (Aquilegia caerulea), also called blue columbine and Rocky Mountain columbine, is the state flower of Colorado. Hardy in altitudes up to 11,000 feet, this columbine variety prefers organic, moist soils in part shade positions. This Ranunculaceae plant family member forms clumps ranging from 12 to 24 inches in both height and spread. Blue and white flowers bloom in April and May. The delicate, green leaves often turn red in the autumn. The Colorado columbine works well in hummingbird gardens, borders and native plant gardens.
Chocolate flowers (Berlandiera lyrata), sometimes called greeneyes, belong to the daisy family (Asteraceae) and do well in altitudes up to 8,000 feet. The grayish-green leaves smell similar to chocolate. Daisy-like flowers appear from April to November, featuring yellow petals surrounding a green or red center disk. Mature flowers range from 12 to 24 inches high. The chocolate flower prefers well-drained soils in fully sunny locations. Colorado gardeners often use chocolate flowers in wildflower gardens, meadows and perennial flowerbeds.
The sticky geranium (Geranium viscosissimum), a perennial in the Geraniaceae family, forms clumps ranging from 12 to 24 inches in both height and spread. This geranium variety prefers moist soils in partly to fully sunny locations. Sticky geraniums grow well in Colorado gardens up to 9,500 feet in altitude. This plant features green leaves that turn red in the autumn. The leaves, stems and stalks feature numerous sticky hairs. Pink or purple flowers bloom from May through August. Sticky geraniums add a dash of color to meadows and native plant gardens.
Rocky Mountain Penstemon
Rocky mountain penstemon (Penstemon strictus), also called the Rocky Mountain beardtongue, belongs in the figwort plant family (Scrophulariaceae). This penstemon variety features spikes of blue to violet-blue flowers that appear in May and June. This fast growing perennial reaches between 12 and 30 inches in height. Rocky Mountain penstemon often suffers from powdery mildew. Rocky Mountain penstemons survive in elevations up to 10,000 feet. This plant prefers dry, well-drained soils that receive partial shade. Colorado gardeners often plant Rocky Mountain penstemon in wildflower meadows and native plant gardens.
Blue flax plants (Linum lewisii) feature vibrant blue, saucer-like flowers from March through September. This perennial performs well in partially to fully sunny locations in elevations up to 9,500 feet. Mature blue flax plants reach from 12 to 24 inches in height. This flax variety features long, bluish-green leaves that gradually drop as the plant matures. This Linaceae family member performs well in Colorado native plant gardens and wildflower meadows.