Selecting the best plants for Colorado

Have you been to your local nursery to check out the 2013 Plant Select winners? Plant Select is a collaborative project begun by Colorado State University, Denver Botanic Gardens and national and regional horticulturists to find, develop and distribute the best plants for the Rocky Mountain region.

By Bridget Tisthammer
Colorado State University Extension Master Gardener in Larimer County

The only woody plant in this year’s selections is a native shrub of the Uncompaghra Plateau, southwest of Grand Junction: Chieftain manzanita (Arctostaphylos x coloradensis ‘Chieftain’) is a much more vigorous manzanita than other Plant Select introductions. In spring, this evergreen groundcover produces oval leaves with a reddish tint and white spring flowers. The leaves darken to a glossy green as the flowers mature into bright red berries by early fall. The Chieftain manzanita’s bark is also striking. Smooth, reddish-purple exfoliating bark develops as the plant matures. The Chieftain manzanita will grow to 18 to 36 inches tall and 5 to 8 feet wide. It prefers full to part sun, well-drained soil and is tolerant of xeric conditions once established. Hardy from USDA zones 5 to 8.

Curly leaf sea kale (Crambe maritima) is a traditional European perennial potherb, with edible leaves and beautiful clusters of shimmering white flowers atop waxy blue foliage. This sea kale begins blooming in spring and continues throughout the summer. It grows to 24 inches tall and 24 to 30 inches wide and prefers full sun and tolerates a wide range of moderate to dry soil conditions. Hardy from USDA zones 4 to 8.

After thirty years on the Federal Endangered Species list, the Tennessee purple coneflower (Echinacea tennesseensis) has been delisted, and Plant Select chose this species to celebrate its recovery. Beautiful purple-pink flowers bloom all summer, always facing east so be sure to site properly. Grows 18 to 24 inches tall and 15 to 18 inches wide. This plant prefers full sun to part shade in moderate to dry sites. Hardy from USDA zones 5 to 6.

The Narbonne blue flax (Linum narbonense) is similar to our western native flax, however, this Mediterranean form is fuller and more long-lived. Sky blue flowers bloom throughout the summer atop a dense, lacy mound of nearly evergreen foliage. It grows 15 to 18 inches tall and 15 to 18 inches wide in full sun to part shade, and tolerates xeric conditions once established. Hardy from USDA zones 5 to 8.

Another Mediterranean introduction is the Turquoise Tails blue sedum (Sedum sediforme). Creamy-yellow flowers rise above succulent turquoise blue mounds in mid-summer and this plant is virtually deer-resistant. It grows 4 to 6 inches tall and 6 to 12 inches wide. Hardy from USDA zones 5 to 10.

Plant Select Petites debuted this year with three introductions. The Plant Select Petites program introduces noteworthy, well-adapted, unusual plants of smaller stature for use in rock gardens, troughs, permanent containers, patio gardens, fairy gardens and green roofs.

Scott’s sugarbowls or Scott’s clematis (Clematis scottii), a diminutive bush clematis from the southern foothills of Colorado’s front range, produces purple, bell-shaped flowers atop a mound of blue-green, lacy foliage in late spring and early summer. Bees and bumblebees are attracted to the blossoms, which are followed by golden seed heads in late summer. It grows 8 to 15 inches tall and 12 to 15 inches wide, but requires full sun and tolerates most moderate to dry soils. Hardy from USDA zones 4 to 7.

Native to high elevation sites in New Mexico, Sandia coralbells (Heuchera pulchella) is a miniature version of the popular coralbells found in many Front Range gardens. Pale pink bells rise above a compact mound of bright green leaves in late spring, which attract frequent visits from hummingbirds and bees. This plant grows in full sun to shade in well-drained soils with moderate to low water, reaching a height of 3 inches tall (8 inches when flowering) and 6 to 10 inches wide. Hardy from USDA zones 4 to 7.

Oxslip primrose (Primula elatior) is a native of moist meadows throughout Europe. This tough little primrose tolerates more heat and drought than most of the primrose family. Fuzzy green rosettes of leaves give rise to clusters of fragrant, soft yellow flowers in spring. It grows 10 to 15 inches tall and 12 to 15 inches wide in moderate to dry soils in partial shade. Hardy from USDA zones 4 to 8.

To learn more about the Plant Select program, visit www.plantselect.org and www.plantselectpetites.org.