USDA Hardiness Zone 6

Plants are known to be cold hardy to at least -10°F.

Other Cold Hardiness categories

Common Name: Hollyhock

Old fashion garden and English cottage garden herbaceous perennial that works well in the Southwest Cottage Garden. Hollyhocks are considered to be either a biennial or perennial. They produce copious seed but are not considered invasive or troublesome. Plant seed in the fall, or early spring.  Avoid watering the foliage if irrigating, a drip system works better that above ground sprinklers.

Common Name: White Swan Purple Coneflower

A beautiful white variety of the purple coneflower. This picture doesn't do the flower justice.

Similar to the purple coneflower, this white variety is really a high water-use plant that appreciates afternoon shade. Deadhead to prolong the bloom period, but keep end of season blooms on for fall and winter interest.

Common Name: Blackfoot Daisy

Native wildflower that likes it lean and mean. Over watering and well amended soil will usually cause Blackfoot daisy to die a premature death, even for a short lived perennial, such as it is. It would be an ideal border plant, similar to alyssum, if not for its tendency to move about where it will (that is, die where you plant it and seed somewhere else). Still, it’s worth a try. Our Panhandle xeric gardens should never be without Blackfoot Daisy. In fact, once you plant Blackfoot daisy and let it seed, you should never be without it (and that’s a good thing).

Common Name: Persicaria, Red Dragon, Red Dragon Knotweed

The most remarkable quality of Red Dragon Persicaria is its burgundy red patterned leaves and red stems, a plant grown much more for its foliage than flowers. (The flower stalk in the upper right is of Acanthus spinosus.) Not a native (native to China) it will come back if nipped by a late frost and will suffer sunburn in afternoon sun. Red Dragon may take 3 years before flowering, however, that is not a drawback.

Common Name: Silver Speedwell

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.

Common Name: Black and Blue Sage, Anise scented sage

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.

Common Name: Perky Sue, bitterweed

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.

Common Name: Artemisia x 'Powis Castle'

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.

Common Name: Fame Flower, Flame Flower, Rock Pink

Fame flower, flame flower, or rock pink, is a Midwestern native succulent. Ideally suited to western rock gardens, short fleshy narrow leaves emerge in late spring, followed by wiry stems where tiny rose/pink flowers open up each afternoon. In fall, the top foliage dies off and the plant heads underground for the winter. Because of it's unusual nature, it can be tucked in anywhere at the front of a border, just don't forget where you've planted it when doing spring cleanup. Reseeds slightly.

Phemeranthus calycinum was formerly known as Talinum calycinum.

Common Name: Curl Leaf Mountain Mahogany

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.

Common Name: Shrub Live Oak, Holly Oak

Shrub live oak, often a medium size shrub, is native to the Southwest and the Texas Panhandle typically found in canyons, rocky cliffs and hillsides. Sometimes called a holly oak, the leaves are 3-4 inches long, spine-tipped and holly shaped bluish green leaves. It is prolific in putting out acorns. Cold hardy, heat and drought tolerant.

Common Name: Buckwheat, Golden Sulfur-flower

Golden sulfur buckwheat is one of those plants you'll come across while hiking in the West and wonder why it isn't in your garden, its so adorable!
The leaves are gray-green, spatula shaped and woolly underneath, to about 2-3 inches. They form a rosette at the base. In early spring, tall, stout stems extend upward up to 2-3 feet. The bright golden flowers are nearly luminescent, appearing first as ball-like umbels (clusters), then each ball opening up to a circle of golden flowers. As the flowers age, then turn orange.

Common Name: Flame acanthus

A native to Texas, flame acanthus loves the heat and full sun! A hummingbird and butterfly plant. Does well in poor soil. May only be cold hardy to Zone 7, however, it has come back for several years in the Panhandle. Grows rapidly and will flower the first year, if you must replant, this is still a good choice for mid to late summer and autumn flowers. Re-seeds some, transplant them early as their roots grow deep.There is another variety with light pumpkin colored flowers, but this one does not bloom as prolificly.

Common Name: Engelman's Daisy, Cut Leaf Daisy

First class native wildflower for your low water-use location whether you live in the city or country. No soil amending is even needed for Engelman's daisy, but you might want to improve the drainage if you soil is compact, or amend with some organic matter for caliche soil. Toowell amended soil will cause E. pinnatifida to grow too tall and gangly. If this happens, cut down nearly to the ground at the end of June, or mid July. It will grow back and begin flowering within 3 - 4 weeks. Will reseed some.

Common Name: Coral bells, Alum root

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.

Common Name: Mock Orange, 'Natchez'

Mock orange is one of those versatile old garden shrubs you can place almost anywhere; it will even flower in deep shade. Fragrant single pure white flowers in spring that may reoccur in the fall with a much lesser show. Drought tolerant once established. The versatility and fragrance must certainly be the reasons gardeners choose mock orange, it certainly isn’t for its irregular shape. I’m afraid I haven’t shown it much respect, allowing its mostly shady corner to be littered with gardener’s menagerie of plastic pots and unused brick-o-brack.

Common Name: Color Guard Yucca

There are numerous interesting yuccas to choose from besides the Yucca glauca or Y. angustifolia seen throughout our area. Y. filamentosa ‘Color Guard’ has some of the most striking variegation and will even flower in part shade, cold hardy to Zone 5. Other Y. filamentosa varieties to consider growing in our area are ‘Bright Edge’ and ‘Golden Sword’.

Common Name: Algerita, agerita, desert holly, Paisano Bush

Native evergreen shrub that makes an excellent hedge plant and wind break. Its blue-green prickly leaves keep the unwanted out (to a point). Please allow room for its spread.

A habitat plant for shelter and as a food source of food for birds and other wildlife that is an attractive addition to the home landscape, where an evergreen shrub is called for in a sunny spot. Sun yellow flowers in March. Cold hardy to -20°, algerita can be found growing from 4000 to 7000 ft. in elevation in Texas, the southwest and Mexico.

Common Name: Golden Current

Golden current makes an attractive taller shrub at the edge of a lawn or vegetable garden, positioned to catch extra irrigation water. For three stunning weeks in spring it will be covered with tiny yellow flowers. I planted two in 2008, and have yet to notice the tasty berries, red currents, for which they are known. Quite cold hardy, if placed in full sun, it'll need twice a month watering to survive, or in half or more shade, once a month watering is sufficient. Multi stem shrub with small, rounded leaves with cut edges makes an attractive barrier or hedge plant.

Common Name: Prairie Poppy Mallow

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.

Common Name: Purple Sage, Desert Sage

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.

Common Name: Mountain Mahogany

Mountain mahogany is native to the Texas Panhandle and throughout the Southwest, found in elevations from 3000-9500 ft. Another common name is Alderleaf mountain mahogany, because its leaves resemble that of an alder. Mountain mahogany, whose wood is very hard (Palo Duro) is found in Palo Duro Canyon. Extremely drought tolerant, it will survive on 10 inches of rainfall. An aromatic shrub with shredding reddish bark, but can grow to tree size. Mountain mahogany's flowers are small, rayless and insignificant, as they are in the other species.

Common Name: Three Leaf Sumac, Skunkbush, Squawbush

Three leaf sumac is medium height woody shrub native to the Texas Panhandle and throughout the Southwest. Three  distinctive cleft and lobed leaves (trifoliate) are medium to dark green. Small greenish yellow flowers in spring are followed by tart red berries in summer, which are used to make a lemonade-like drink. The shrub's flowers have a pleasant fragrance, even though it is called skunkbush by some. Beautiful golden and reddish fall foliage. Cold hardy to Zone 4, yet extremely heat and drought tolerant. Prefers sandy and well drained soils.

Common Name: Texas Sacahuista, Texas Beargrass

Texas beargrass is a grass-like perennial evergreen plant native in rocky and limestone soils from central Texas to the upper Rio Grande Plains and west to the Trans-Pecos and into S.E. Arizona. Not a true grass, Texas sacahuista is a member of the lily (Liliaceae ) family. It flowers in Amarillo in early April. A short flowering stem barely rises above the many thin leaves. The flowers appear rose or reddish on the outside before opening,  are numerous, white to cream colored forming dense vertical clusters.

Common Name: Sea Foam Curlicue Sage

Artemisia versicolor 'Sea Foam' is mostly grown for its gray foliage. To keep it's desired compact shape, cut off flower stalks after blooming, which is its only maintenance. Soft, rubber-like feel to its short, clustered, needle-like appearance on short 1 inch wide columns. It gives the impression of a coral bed in your rock garden. Not invasive. 2004 Plant Select Plant.

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