Plants are known to be cold hardy to at least -10°F.
Agastaches are some of the Southwest's showiest natives and one of our native perennials where must breeding and hybridization is being done. Native to slightly higher elevations that 3600 ft., it requires either afternoon shade or medium water-use. It has not been reliable in coming back for me, but it has for others. Well drained soil is a must. Nonetheless, it is easy to be seduced by its masses of blooms and alluring fragrances. Hummingbirds certainly are entranced.
Yellow honeysuckle is a much better choice, along with Loncera sempervivens, than the traditional and invasive Japanese honeysuckle usually sold. Fragrant and yellow blooming, a good climber and groundcover. Average garden soils with low and medium water-use. Can be low water-use once established.
Switchgrass is one of the best native ornamental grasses of our tall prairies. Switchgrass forms upright bunches of wide 1/2 inch green blades, with open pale purple inflorescence arising another 2 feet in late summer to fall. Switchgrass will thrive with every other week supplemental irrigation. There are many varieties of switchgrass, 'Prairie Sky' is the most drought tolerant (low, xeric) with blue blades. Other fine selections are 'Heavy Metal' with metallic lavender blue foliage turning reddish towards fall, and 'Shenandoah' with leaf blades tipped in red.
Lavender cotton, or gray santolina is a low mounding woody subshrub that should live on the lean side. Not that it won't overgrow if fed. It will maintain its compact shape in poorer soils without amending or fertilizing. Small silver gray leaves cover the shrub. Tiny yellow button flowers appear in summer. Evergreen, the santolinas are native to the Mediterranean area. Aromatic and edible, it's leaves were used as a flavoring in broths, sauces and grain dishes. Low water-use.
Daffodils are the most notable of the spring bulbs. Reliable from year to year, daffodils can be depended upon to bloom even when faced with late season blizzards and are unpalatable to deer and squirrels. Daffodils aren't too particular about soil, but do better in amended soil, planted about 4 inches deep in November and December. Typical bloom times are February through April, depending on the variety, and there are thousands of varieties to choose from.
Although usually sold as Clemantis paniculata, it could be C. terniflora. Sweetly fragrant, low water-use vigorous growing vine for great late summer display. Creamy white flowers form silvery seed heads. Cut back in spring as it blooms on new growth.
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.
Gorgeous! Luscious goblet shaped lemon yellow flowers on this native wildflower that also develops elongated seed capsules. The lighter, silvery sheen of the leaves distinguishes the O. macrocarpa var. incana subspecies, and is also an evening to morning bloomer.
If I had to pick my favorite plant, this is it. Long blooming and drought tolerant with only minimal maintenance of late winter cutting back, and maybe a bloom pick-me-up deadheading at mid summer. It will also re seed some so you’ll have more of them the next year. It’s fragrance is light and pleasantly of sage. Salvia greggiis are native to Texas in the Kerrville area. It is my favorite, but not the absolutely perfect plant. The stems are quite brittle and very easily break or snap off, even when you’re carefully weeding around it.
Most gardeners’ acquaintance with veronicas is with the Veronica spicatas, ‘Red Fox’, ‘Icicle’, and ‘Sunny Border Blue’; the tall, spiky red, white and blue medium and high water-use veronicas. But consider the low water-use option, V. incana. Deadhead to prolong the blooms and water deeply once a month, once established in well-drained soil. The gray-green leaves should be a give-away by now as to its water requirements.
Previously known as Cowenia mexicana, it is known today as Purshia stansburyana, also, P. stansburyiana. It is still commonly called a cliffrose. The cliffrose blooms prolifically in May with creamy white to pale yellow fragrant flowers that continue blooming for several weeks. Semi evergreen, it loses it's leaves in colder winters. Upright stems and branches can appear unruly in its growth pattern; small dark green resinous leaves.
Big Bend silverleaf is the most cold hardy of the Leucophyllums and has wintered over in Amarillo, Zone 7, for 5 years so far. Possibly cold hardy to Zone 6. It is hard to beat a more attractive summer blooming shrub for small xeric spaces. After summer rainfalls, Big Bend silverleaf, native to the Big Bend National Park area, becomes covered in silver blue flowers that twinkle like jewels among its silvery gray leaves. Hard to find, it's worth searching for.
Another American native vine, evergreen in more southern climates than ours, but cold hardy here. Fragrant and attractive coral flowers in spring and early summer. Attracts birds, butterflies and hummingbirds. Pleasant glossy green leaves. Not invasive. Medium water-use.
Alkali sacaton is a perennial warm season bunch grass native to the Southwest. In late summer to fall, airy triangular seed heads wave above the silver green grass blades. Grows in alkali soils, many say in locations where there is moisture nearby, prefering heavy clay soils. It is quite drought tolerant once established, and long lived. It will, of course, grow bigger or smaller depending on water resources.
Green santolina is an evergreen shrub native to the Mediterranean region. Its grass-green color makes it a welcome addition to any landscape. Medium and low water use, cold hardy, sun and heat tolerant, it prefers poorer soil. Aromatic green leaves that resemble those of the cypress. Yellow button flowers in summer.
Mat daisy is a low growing spring blooming plant. Drought tolerant. Not exactly a groundcover, as the top growth disappears during summer and reemerges as a green basal rosette in fall, getting ready to bloom again in the spring. Blooms late March to May with small white daisy-like flowers that have pink undersides. Forms a compact ground-hugging mat. Will self seed some, but never invasively.
Many Aquilegia’s are native to the U.S. Golden columbine, Aquilegia chrysantha is a Texas and southwest native, has yellow flowers and can take more sun than some varieties. McKana's Giant is the hybrid columbine most often sold. Large beautiful bi-colored flowers dazzle in woodland and shady area. Rocky Mountain columbine, Aquelegia caerulea; and wild columbine, A. canadensis, are other common columbines. Rocky Mountain columbine is the state flower of Colorado.
The old fashioned larkspur is a drought tolerant reseeding annual, previously associated with delphiniums (now in the Ranunculaceae family). I’ve grown it in my alley, in the xeristrip, and its crept into my medium water-use zone. Deadheading keeps millions of tiny seeds from overcoming your garden next year, and also keeps the blooms coming. Larkspur can flower for six weeks. Again, deadheading is important to prevent a massive infestation throughout your landscape.
Heucheras are native to the North American continent and make wonderful foliage and flower plants for your woodland border. Grown mostly for its interesting, evergreen foliage, coral bells will continue to flower on mature plants if kept deadheaded into the summer. Although the native heucheras are great in themselves, there are hundreds of hybrid cultivars to choose from.
Exciting perennial ornamental oregano for your low water-use or Mediterranean style garden. Spreads slowly by rhizomes and is easily propagated by root cuttings in fall or early spring. The flowers elongate as the summer progresses, eventually drying to a papery brown by summers end. In a wet fall, some new flowers may still appear. O. libanoticum is best placed to drape over a rock to showcase it’s drooping nature.
There are several varieties of Salvia guaranitica that range in shades of blue from light to dark. As with most of the tube-shaped salvia flowers, S. guaranitica is a hummingbird magnet.
Native to South America, S. guaranitica is not zoned cold hardy for the Texas Panhandle, but it has wintered over in protected Amarillo gardens in many locations for many years. It has wintered over for me at least 5 years, unprotected. Deadheading is not required.
Low growing, drought tolerant evergreen groundcover that becomes covered in tiny sky blue flowers in early spring for about 6 weeks, then sporadically throughout the year. I’ve seen a few twinkling blue blooms in every month of the year. The tiny leaves of V. pectinata are gray-green and tomentose. Allow plenty of room for the spread of this fabulous groundcover; it’ll just keep going and going and going. And you won’t want it to stop.
Scarlet globemallow is a welcome addition to any xeric or High Desert garden. Small coral flowers bloom from May (sometimes April) through into the fall. Although scarlet globemallow will survive with no additional moisture in our climate, once a month watering insures steady blooms. The plant is similar in appearance to S. ambigua, which can bloom coral, white, lavender and pink.
Agaves are striking and architectural Southwest native plants and are included in a group of plants I term Southwest evergreens. They are unusual in that at maturity, they only flower once, and then die. for this reason, some classify them as multiannual, rather than perennial. However, as they common name suggests, it takes many years before they flower. Leaves of the Agave are arranged in a spiral beginning from a near invisible stem, forming a rosette.Agaves vary in size from 4-6 inches to larger than man-size.
Tansy aster is an annual native to the Southwest and throughout the Plains even into Canada. Fernlike, or tansy-like (tannacetifolia) light green foliage with beautiful aster-like lavender flowers with yellow disks about 1 1/2 to 2 inches across. Blooms from late spring through fall. A once a month watering will keep the blooms coming throughout the summer. It will keep its compact shape in lean, poor soil but will become much larger in well amended soil. Minimal amending is recommended. Tansy aster is another example of our natives plants giving so much, asking so little in return.