High Plains Gardening
The gardening website of the Texas High Plains Region
USDA Hardiness Zone 6
Plants are known to be cold hardy to at least -10°F.
‘Red Rocks’ is another hybrid cultivar, named for the Denver, Colorado red sandstone area and amphitheater. P. 'Red Rocks' is highly suitable for the average garden, rather than a specialized penstemon bed. Again, do not deadhead unless reblooming has occurred and you desire a tidier appearance. Don’t over water or over amend the soil, but it will thrive companionably with other medium water-use plants.
A non-invasive tansy from southern and central Europe for your low water-use bed and border that will reseed somewhat. A short lived perennial. Gray cut-leaf foliage provides an attractive white element in the garden.
Strongly aromatic.
Sedum, ‘Autumn Joy’ is one of those foolproof additions to your autumn garden, so aptly named; for the joy it brings to the autumn garden. Easily propagated by stem cuttings or root division. As with most sedums, afternoon shade helps. Grasshoppers have nibbled at its leaves in early summer without stunting the plant’s flowering ability.
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.
Giant sacaton is one of the largest bunch grasses native to the Southwest, like alkali sacaton on steroids. Seems to thrive in poor soils with no supplemental irrigation. It will grow even bigger with added moisture. Thick textured grass blades, it will rival pampas grass for size and beauty, although it plumes are near as showy, giant sacaton has a flowing fountain appearance. A warm season grass, it is cold hardy and thrives in sun and heat.
Bear grass is similar in appearance to yucca and clumping grass, but is neither. Usually found growing in high desert areas, along cliffs and rocky slopes. Thin succulent grasslike yellow-green leaves emerge from a trunkless center, are pointed and sharp edged. A plume-like inflorescence with many tiny cream colored flowers emerges early summer. Cold hardy, drought and heat tolerant.
Hyacinths are a much loved and very fragrant spring bulb, flowering in March and early April in our area. Clusters of bell-like flowers dangle from a central stem. Native to Asia, hyacinths were one of the early favored flowers by the Persians, Turks and Europeans, in fact, practically everyone who came in contact with them. Easy to grow in full sun to part shade in average garden soil. Hyacinths come in many pastel colors, both single and double flowers.
An old world Mediterranean plant best known for the acanthus leaf shape used as a basis in classical Greek and Roman designs. The plant itself takes 2 – 3 years growth before flowering. Attractive flowers with purple bracts on tall spikes to 4’. Frost sensitive, will die back in a late spring frost, but will come back. Adds architectural and textural interest.
Delicate fern like foliage for your shaded woodland areas. Will grow in a low water-use zone, however, the foliage will disappear in summer. Delicate tubular, yellow. White and blue varieties have been available locally. An excellent choice for underplanting trees, especially for a medium water-use zone. Will reseed.
Outstanding shrubby perennial fragrant herb for the garden! Very good soil drainage is the key to growing lavender, it does not like moist, compacted clay soil. Lavender appreciates supplemental irrigation every 2-4 weeks, if not provided naturally. Trim back in late winter or early spring by not more than a third, or just trim down last years flower stems. Triming too much off the plant will kill it.
A long-lived evergreen penstemon for the average bed or border. Small orange red tubular flowers attract hummingbirds, as do most red tubular flowers. Low growing and longer flowering than most, especially the more mature the specimen.
After several years, the pine needle like foliage can resemble a miniature bonsai. Pineleaf penstemon is also a must-have for the low water-use bed or border or rock garden because of its evergreen foliage and longer blooming nature. In late summer, snip off the dried, spent flower heads; some re-blooming may occur.
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.
Veronica x ‘Blue Reflection’ should be an indispensable evergreen groundcover for you, as it has become for me.
Desert globemallow is one of those native plants that keeps on giving, asking so little in return and is a worthy addition to any native or xeric garden. Typically, desert globemallow sports pretty pink flowers. though some plants will bloom white, coral or lavender. Whatever color, they are worth the addition to your sunny and dry landscape for their pleasant cheery nature. Similar to appearane to S. coccinea, a coral blooming species.
Not all succulents are cacti, nearly all cacti are succulents (a few exceptions). Nearly all cactus species are native to the Americas, providing a prickly evergreen presence. There are many cactus that are cold hardy for the Texas Panhandle. There might be one for your garden.
Bigelow's tansyaster is easy to confuse with Tahoka daisy but is not as showy. Bigelow's aster is a fall blooming biennial, with far fewer purple rays and a smaller, yellow brown center disk. It populates plains in Colorado, Arizona and New Mexico. In the fall, whole fields will wear a purple haze due to this tansyaster.
Prairie dropseed is smaller than both alkali or giant sacaton, more fitting for the city garden. A warm season bunch grass, prairie dropseed is a most attractive low or medium water-use grass with graceful green foliage. The seed heads emerge in late summer into fall with light pink seeds, that is said to naturalize some, but not invasively. A slow grower. Foliage turns a pleasing golden orange in the fall. Native throughout the Great Plains, including Texas. Tolerates most soil conditions.
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.
Small green gray evergreen leaves forms mounded, low growing xeric plant with small white flowers in late spring. Does not spread vigorously. Easily propagated by root cuttings. An alpine from the Balkans region.
Perennial from South Africa noted to be cold hardy for our area, but I’ve had mixed results, most years it didn’t winter over (although reported to be Zone 5). However, it will flower nicely the first year in the garden, so I’ve kept trying it. A Plant Select Plant for 2000. Perhaps it needs moister conditions in the winter than what I give it.
The only draw back to this pretty, silver-edged groundcover is its flowers! If only it didn’t, it would be a perfect no maintenance, no water groundcover for hot, sunny locations. You can see the tiny ball shaped flower heads in the picture, which look rather indistinct. However, after flowering, they turn an ugly shade of brown that mar the beautiful leaves unless you shear them off. Though a creeping groundcover, silver-edged horehound is not invasive like the common horehound, M. vulgare.
‘Mersea Yellow’ is similar to the orange red pineleaf penstemon in culture, except for requiring a bit more water. Native perennial to the Southwest. Its leaves are lighter green, but still evergreen, without the tinge of mahogany in winter. ‘Mersea Yellow’ is an excellent selection for the medium water-use zones of your landscape. One of the few yellow flowering penstemons.
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