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Plant selection color wheel

by Timber Press on May 25, 2017

in Design, Gardening

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Picking the right plant can feel picky, but with these resilient, water-smart suggestions from Plant Select’s Pretty Tough Plants, you can use color theory to make the right pick!

Rudbeckia ‘Denver Daisy’

Size: 18–28 in. tall, 10–25 in. wide
Flowers: yellow with a dark eye ring, summer through fall
Best features: large yellow daisies with darklined centers; long season of showy bloom


Rudbeckia hirta brightens roadsides from the Rockies to the Appalachians and has been a cherished garden plant around the world for over two centuries. In recent decades, a wide spectrum of selections has been made for height, flower form, and habit. This flamboyant hybrid is deemed by many gardeners to be the most spectacular.


Full sun. Clay or loam; performs best in good garden soil. Moderate watering to dry; grows best with moderate irrigation during the hot and dry times of summer. Although it can occasionally come back and bloom a second year, it is best treated as an annual. Self-sown seed does not always come true to type. Propagate by commercial seed sources that breed true, or as plants purchased and planted in late spring. USDA hardiness zones 6–9.


Denver Daisy is easily grown in a variety of soils and exposures provided it’s not given too much shade. In containers, the showy blooms and compact, sturdy plants create a vivid show in late-summer and fall-themed combinations. Ornamental grasses such as Korean feather reed grass, Blonde Ambition blue grama grass, or WINDWALKER big bluestem combine well with Denver Daisy. It also pairs wonderfully with Ruby Moon hyacinth bean and winecups. Attracts bees, butterflies, and moths. Deer resistant.


The parent species, Rudbeckia hirta, is native to the Rocky Mountains and midwestern prairies. When introduced by Plant Select in 2009, this hybrid from Benary Seed was a fitting sesquicentennial tribute to the founding of Denver.

Arenaria ‘Wallowa Mountains desert moss’

Size: ½ in. tall, 8–12 in. wide
Flowers: inconspicuous, white, spring
Best features: bright green cushion year-round; wonderful texture; xeric


For water-wise gardeners, the bright green, tight-growing foliage is a welcome contrast in color and form grown for its cushion-forming mats of green.


Full sun to partial shade. Well-drained loam or sandy soil. Moderate watering to xeric. Very low maintenance if cultural conditions are met. Propagate by cuttings or divisions. USDA hardiness zones 4–8.


Desert moss is a useful and attractive plant for troughs, rock gardens, and fairy gardens, between paving stones, or as a contrast in xeric gardens with hardy cacti and succulents. It makes an excellent green roof plant in partial shade. It also tolerates the heat and humidity of the Midwest and Eastern United States. Gardeners in western states or in drier areas should consider desert moss as a true moss alternative, particularly in Japanese-style gardens or other small areas where the look of turf grass can be mimicked. Goldhill golden-aster, Scott’s sugarbowls, low-growing sedums, and ice plants all make good pairings for desert moss. Attracts bees. Deer resistant.


Boyd Kline discovered this plant in the Wallowa Mountains of Oregon and Washington. It was introduced by Siskiyou Rare Plant Nursery, originally as a form of Silene acaulis, but upon flowering was determined to belong in the genus Arenaria.

Veronica ‘Reavis’

Size: 2–3 in. tall, 20–32 in. wide
Flowers: blue, late spring through early summer
Best features: profusion of bright blue flowers; vigorous spreading habit; xeric


CRYSTAL RIVER is a spontaneous hybrid between Veronica liwanensis and V. pectinata with the bright green leaves of the former and the vigor of the latter. The evergreen foliage adds winter interest as the leaves have a purplish tinge in the cold months. The medium blue sparkling flowers of CRYSTAL RIVER bloom in late spring to early summer and are timed right between its parents, adding another hue of blue in the spring garden.


Full sun to partial shade. Clay, loam or sandy soil. Moderate watering to xeric. Requires little care. Tolerates low water conditions and alkaline soil. Spreads rapidly but not aggressively. Propagate by stem cuttings or plant divisions. USDA hardiness zones 3–7.


CRYSTAL RIVER veronica is an excellent border perennial or groundcover and can be planted either individually for accent or in masses or drifts. It does well in a rock garden or xeriscapes, especially when tucked among rocks or between pavers. Fast growing, it will form a somewhat tight mat fairly quickly. CRYSTAL RIVER veronica is excellent in a rock garden as it cascades down a rock wall or walkway, giving the impression of a blue river. Plant it beneath shrub roses, Engelmann’s daisy, or thread-leaf coreopsis (Coreopsis verticillata). It combines beautifully with other groundcovers such as KANNAH CREEK buckwheat, and ice plants. Deer resistant.


Found at Denver Botanic Gardens in 1998, this natural hybrid is a cross between two species native to Turkey.

Verbena bipinnatifida VALLEY LAVENDER

Size: 3–6 in. tall, 12–18 in. wide
Flowers: purple, spring through fall
Best features: cold hardy; long bloom period; vibrant lavender-purple blooms


Introduced by Plant Select in 2005, VALLEY LAVENDER is highly cold and drought tolerant. Even when it’s not flowering heavily, the highly dissected, gray-green foliage is very attractive. With only occasional watering, it can bloom all summer and may even bloom into early winter in mild years.


Full sun. Well-drained clay, loam, or sandy soil. Moderate watering to xeric. Prefers native soil. May not be as cold-hardy in soil with high clay content. Intolerant of heavy shade or excessive watering. Propagate by tip cuttings which easily root. USDA hardiness zones 5–8.


VALLEY LAVENDER plains verbena can be used in a rock garden, xeriscape, or meadow, and looks especially nice cascading over a wall or in the front of a dry border. This groundcover looks as good in a formal garden as it does in a wild setting. The luminous lavender flowers combine especially well with bright yellow flowers of KANNAH CREEK buckwheat or Gold on Blue prairie zinnia. It also pairs well with manzanitas and dwarf piñon pine. Attracts butterflies and hummingbirds; a good source of nectar.


The species is native to Great Plains of North America south into Central America, and the strain was developed by Little Valley Wholesale Nursery in Brighton, Colorado.

Rhus trilobata ‘Autumn Amber’ sumac

Size: 10–14 in. tall, 6–8 ft.+ wide
Flowers: inconspicuous, yellow, late spring through early summer
Best features: ground-covering habit; glossy leaves; very xeric; fall amber color depending on seasonal conditions


Creeping Autumn Amber sumac is quickly becoming the go-to choice as a xeric deciduous groundcover option instead of wood mulch. It thrives under natural precipitation once established and is a beautiful and perfect plant for tough, open areas. The glossy green leaves of summer turn yellow in autumn.


Full sun. Soil: loam or sandy soil. Moderate watering to xeric. Minimal maintenance unless trying to shape the plant into a small space, in which case trim it once or twice a year. Use hand trimmers to prune horizontal branches that lay too close to the ground to use electric trimmers. The branches will eventually root down so if containment is desired it’s best to keep branches trimmed on a regular basis. Fall leaf litter clean-up is generally not needed in windier locations, otherwise rake or blow the leaves in fall to remove leaf litter and debris. Propagate by cuttings, which are difficult to root. USDA hardiness zones 4–8.


Use Autumn Amber sumac as an individual or in masses cascading over boulders or the edges of retaining walls. It does well in hot, sunny slopes and green roof situations, or can be used as a living mulch among tall shrubs. It can be planted under xeric shrubs such as fernbush, mixed in with
bluestem joint fir or with other ground-covering shrubs such as PAWNEE BUTTES sand cherry and the Colorado manzanitas. Deer resistant.


The species is native to the western United States from Mexico to Canada and the cultivar was discovered in Littlefield, Texas (near Lubbock), growing out of limestone outcroppings.


Plant Select® is a leading non-profit cultivator, distributor, and educator of plants designed to thrive in the high plains and intermountain region, and anywhere that water resources are of concern.




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