A perennial plant is a plant that requires one or more years to reproduce and usually continues living, but not indefinitely. Whether a plant is cold hardy or not is not connected to being an annual, perennial or biennial.
Black dalea, an autumn blooming southwest native shrub, should be used more in the home xeric landscape. Growing only to about 3 feet, black dalea spreads out with thin, wiry branches and small, green, compound leaves. The shrub becomes completely covered with tiny purple flowers as to be enshrouded in a purple cloud.
Many references are unsure of its cold hardiness to zero, and it had thrived nicely in my city garden in Amarillo. However, it does not seem to be reliably cold hardy. It's a beautiful shrub that provides stunning late fall color that is worth replanting.
Small but tough is Perky Sue. Woody base with thin short green leaves from which many stems shoot up to display many yellow daisy like flowers from April into fall. Many people know this plant by the genus name Hymenoxys, but has been changed to Tetraneuris in the last decade. There are a few relatives that look quite similar and are all equally valuable in the garden: T. acaulis and T. odorata.
Low water-use non-native hybrid shrub (Artemisia arborescens x Artemisia absinthium) from Europe and Asia. Vigorous grower, do not overwater. Coldy hardy to Zone 6. Ever-silver with elegant finely cut leaves. 'Powis Castle' is named for Powis Castle in Wales. Rarely flowers.
For more information and a list a gray and silver leaved plants, read Fifty Shades of Gray, my most viewed page.
Purple or desert sage prefers leaner, quick draining soils. It is said to grow 2-3 feet tall and deeply branched with silver gray foliage and a profusion of violet bluish flowers atop spikes in late spring and summer. Low water-use, but does better with once a month irrigation. One of the finest flowers of the desert, it is the sage of Riders of the Purple Sage, by Zane Grey. Grows throughout the Great Basin Desert.
Littleleaf mountain mahogany is the shortest of the mountain mahoganies usually sold. Small, narrow, leathery looking evergreen leaves on many intricate branches. Small yellow flowers in springtime and feathery seed plumes in the fall. The shrub is densely branched and slow growing.
Littleleaf mockorange is native throughout the foothills, dry rocky slopes and open woodlands from 4000 to 8000' in the Southwest usually growing to only 4 feet. This native mockorange is similar in form to the European import, they are fragrant, but not of orange. Attractive white, 4 petaled flowers bloom in early summer, small slightly glossy green leaves. Coldy hardy, heat and drought tolerant.
A great plant for those people who must have their foliage fix. Despite their large foliage, cannas will do quite well in a medium water-use area with well amended soil.There are dwarf varieties and others that will reach 7 feet. Leaves shred easily by hail, but will recover after several weeks. Cannas sprout from thick rhizomes. Although subtropical, cannas easily winter over in the Texas Panhandle and spread to form a thick root mass.
Green sword-like foliage with striking bell or funnel shaped flowers that last only a day. Hundreds of different hybrids and cultivars in a wide range of colors, some early, mid and late summer blooming. Daylilies do better in medium, well-amended soil and a sunny location that enjoys afternoon shade, but they are versatile. Daylily leaves may exhibit alkalinity in clay soil. If this is the case, amend well with organic matter.
This is not one of the invasive catmints, but it will reseed some and is not as attractive to cats as most catmints. A low growing, sprawling, drought tolerant perennial that projects a hazy blue appearance with its light lavender blue flowers and grayish green foliage. It is aromatic, not necessarily fragrant. A fast spreader and prolific bloomer even in it's first year, it will begin to bloom after six weeks.
Unlike, S. nemorosa ‘May Night’, I don’t mind deadheading this salvia, perhaps because of its plum color it does not require as persistent deadheading. Notice the gray-green leaves of ‘Plumosa’, versus the green leaves of ‘May Night’. The stems tend to flop, but the flower stalks continue to grow and flower upright -- very strange.
A Plant Select Plant for 2004, Pink Texas Skullcap has often been listed as a Zone 7 plant, but it is reliably cold hardy in Zone 6 and in protected Zone 5b sights. I’ve grown it in my xeristrip since 2000. Long blooming with no maintenance ever performed. These low growing, mounding skullcaps are excellent for Panhandle xeristrips and rock gardens. Native varieties are S. drummondii, and S. resinosa. The hybrid cultivar, S. x ‘Violet Cloud’, introduced by High Country Gardens, is an excellent violet skullcap as well as the natives.
If you find yourself in Palo Duro Canyon at the end of April or beginning of May, the purple haze dotting the cliffsides is feather dalea. Sporadic blooms will open after showers throughout summer, though never as profuse as in springtime. With monthly irrigation in a xeric garden, feather dalea adds color and texture with it's twiggy, but sturdy, appearance. Small purple flowers combined with white plumes carries the haze impression from a distance.
Warm season native clumping ornamental grass that is well suited to the transition zone between turf and flower bed. Medium to blueish green thin grass blades form a low to medium size clump, medium water-use zone. In late September, it sends plumes upward that give the appearance of a deep pink haze or mist. There are several new selections of Gulf Coast muhly, thankfully, to choose from. Be sure to pay attention to the cold hardiness for your area and you won't be disappointed.
Similar in form to Callirhoe involucrata, Callirhoe alcaeoides 'Logan Calhoun' grows natively from the Midwest to southern plains. While Callirhoe alcaeoides can be pink, to pale pink and pale lilac, 'Logan Calhoun' is pure white. Spreads over an area similar to wine cups, the foliage and flowers are finer. I've found it to be drought tolerant; water monthly to insure continued blooms. Blooms will rest during the heat of the summer and continue following rains or cooler weather.
Raspberry hybrid bush sage is very similar in appearance to Salvia greggii, blooming April through November. It's two-lipped flowers with a pleasant deep raspberry color, and the mahogany calyces contrast nicely. 'Raspberry Delight' is a hybrid cross between Salvia greggii 'Furman's Red' and and a high altitude collection of Salvia microphylla from central Arizona. Woody and brittle branches with small oval shaped leaves that hang on to the plant sometimes through the winter, as they do on S. greggii.
Curl leaf mountain mahogany is a medium height evergreen shrub native to elevations between 5000-10,000 feet throughout the Southwest. Small oval shaped dark green leaves lightly curl under at the margins are evergreen and aromatic. Small yellow flowers in spring time that develop into grain size fruits with a feathery tail attached to one end (similar to other mountain mahoganies). Slow growing and long lived, it can reach a height of 20 feet or more, but is more typically 6-12 feet. Densely branched. Cold hardy, drought and heat tolerant.
Western sand cherry is a shrub native to the northern plains favoring sandy soils. Cold and heat tolerant, and low water-use once established. Beautiful, fragrant white flowers in spring time, producing edible black cherries (however, some references advice not to eat the fruit if it is bitter).
Delicate and fragile in appearance, columbines are some of the most durable, versatile plants in the West. Aquilegia chrysantha is the Texas native columbine, happy in both sun or shade, moist areas or dry. Aquilegia chrysantha is native to the Chihuahuan and Sonoran Desert canyons from west Texas, southern New Mexico, southern Utah, and Arizona south into Sonora, Coahuila, and Nuevo Leon along with a disconnected population in southern Colorado.