AHS Heat Zone 9+

Plants that will live in areas that experience 120-150 heat days (AHS Heat Zone 9) each year where temperatures exceed 86 degrees F. Except for a few limited areas in the Texas Panhandle, our AHS Heat Zone is 8. Plants rated lower than AHS Heat Zone 8 may not survive the summer's heat.Plants rated higher should do just fine.

Other Heat Zone categories

Common Name: Mexican Blue Sage

Mexican blue sage is a native of Mexico and in many references labels it cold hardy to USDA Zone 8, however, it has wintered over in Amarillo many years now, even in full northern exposure. It has died back to the ground once or twice, but comes back up from the roots. If good to well drained soil is provided, it should do fine. And I hope you can provide that, as Mexican blue sage is one of my top plants to include in xeric gardens. True bright blue flowers bloom summer and fall with once a month watering. Butterflies are attracted to it. Indispensable.

Common Name: Gooseberryleaf globemallow, Current leaf globemallow

Gooseberryleaf globemallow is very close in appearance to scarlet globemallow, Sphaeralcea coccinea, but much taller, up over 2 feet. The leaves are silver green and hairy, resembling the leaves of the current shrubs in shape, so named from the family name of currents and gooseberries, Grossulariaceae. Flowers are orange in color and bloom from May and June, sometimes later in the summer. Native to hot, dry areas semi-arid regions throughout the Southwest and the Great Basin Desert. Prefers good to sharp drainage.

Common Name: Santa Fe Phlox

Santa Fe phlox is rarely available even at native plant nurseries, but when it is, don't pass it up. Sun loving and drought tolerant, the Santa Fe phlox blooms late spring throughout the summer with once a month watering. Five petaled, small pink flowers about an inch across with a small white eye can cover the plant. Native to canyons, mesas, and rocky desert slopes from West Texas to southeastern Arizona and into northern Mexico. Seeds of the phlox pop out when they are mature, making seed collection and propagation difficult.

Common Name: Mohave Sage

Beautiful xeric sage with aromatic soft gray green leaves, mostly evergreen. Summer to fall blooming with mauve/purple sticky but fragrant flowers. Takes a few years to reach mature height. Requires good drainage and dry soil in the winter. A Plant Select® Plant. Native to California and will grow in the High Desert regions. Cold hardy to Zone 5 and quite heat tolerant.

Common Name: Shadscale

Shadscale lives in alkaline caliche soil in most of its native range throughout the Southwest and has a high tolerance of saline or sodic soils. Given improved soil conditions, it will grow larger. Do not improve the soil to insure it keeps its neat, compact shape. Shadscale blooms yellow flowers in early summer which mature into seed heads. Its silver-gray leaves are semi-evergreen.

Common Name: Caladiums, angels wings, elephant ears.

Caladium bulbs are tropical plants grown for their summer foliage, however they do send up an arum type flower (a member of the Araceae family). Foliage comes in many different variegation patterns in red, pink and white. Plant bulbs after May 1st, only about 3 inch deep. Caladiums like it hot and moist. Complete shade works OK, or morning sun only. For larger leaves. keep the bed or pot well moist, especially during bulb germination. High water use plants can be used for small areas of the landscape or pots.

Common Name: Scarlet hedgenettle, Texas Betony

Texas betony is a workhorse of the garden once established, putting on a plethora of scarlet blooms midsummer on. A member of the mint family with square stems, the foliage is fragrant, but the plant is not invasive as classic mints tend to be. Hummingbirds love Texas betony. Though native to the Southwest, it is found in moist crevices and steep, stony places in the mountains in moist, well-drained sand, loam, and clay. Texas betony is said to be cold hardy to -20°, however, I have not found it reliable in returning each winter. Yet, it is worth replanting.

Common Name: Amaryllis Hybrid cultivar

Typically a Zone 8 plant, the Christmas holiday bulb, Amaryllis, has been successfully wintered over in Amarillo, specifically, the Wolflin area in this case. If you have a warmer, protected micro-niche, try planting your seasonal Amaryllis outdoors, and leave it there well mulched over winter. I 've winter over Amaryllis in my backyard, but it hasn't reliably bloomed. It requires a full sun location and well amended soil to soak up nutrients to be stored in the bulb.

Common Name: Chisos Rosewood

The Arizona rosewood is classified either as a quite tall shrub or short to mid height tree. One of it's best features is that it is evergreen, with slender glossy green leaves approximately 3 inches long. It puts on small white flowers in summer. One of the few drought tolerant, native, evergreen trees available in the trade. Slow growing.

Common Name: Blackie, Ornamental Sweet Potato Vine

A tuber mostly grown in containers or a summer groundcover, not considered cold-hardy in the Panhandle. Striking purple-black foliage with small light magenta flowers, similar in appearance to bindweed. Ipomoea’s are members of the bindweed family, Convolvulaceae. One bad relation doesn’t have to trash the family, however.

Common Name: Arizona Rosewood

Arizona rosewood is one of the few native evergreen trees or tall shrubs that are low water-use. Underused in the Texas Panhandle, mostly due to lack of availability. But with searching in Albuquerque or Santa Fe, one should be able to locate a specimen. Faster growing than the Chisos rosewood. Long slender, serrated, glossy green leaves with white flowers in summer.

Common Name: Standing cypress.

Reseeding biennial, native to Texas, and the southeastern US. The red tubular flowers make it attractive to hummingbirds. The upright stalks are brittle and break off easily.

Standing cypress will flower the first year, and may, or may not come back a second year, but you should see some seedlings. Transplant those. The glossy green foliage to the right in this picture belongs to Anisacanthus quadrifidus wrightii, flame acanthus.

 

Common Name: Big Bend Silverleaf

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.

Common Name: Crape Myrtle

Grown in the South for decades, most people think of crape myrtle as a native American plant; it is however native to China and Japan. Small tree or large shrub that is cold hardy to Zone 7.  I’ve grown the same crape myrtles for over 20 years, but they’re planted close (too close!) to my bricked house on both the northeast and northwest corners. They’ve been stem hardy, not just root hardy, and have grown up to about 10-12’. In most cases, crape myrtle will not grow into tree form in the Panhandle, but there are mature, tree size crape myrtles in Amarillo.

Common Name: Century Plant

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.

Common Name: Select Blue Catmint, Catnip

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.

Common Name: Cactus

Not all succulents are cacti, but all cacti are succulents. Nearly alll 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.

Common Name: Salvia darcyi

The flowers of Salvia darcyi are similar in appearance to Salvia greggii, however the shrub itself is more herbaceous than shrubby. I know of no common name for S. dacryi. Some sources say it is cold hardy to Zone 7, however it thrives in Denver Botanical Garden’s Zone 5. S. darcyi is native to the mountains of Northern Mexico and will do well in amended soil. Hummingbirds love it.

I have it planted in my xeristrip for a number of years. It will flower more vigorously with irrigation everyother week, when needed during hot drought years.

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.

Common Name: Chamisa, Rabbitbrush

Chamisa or rabbitbrush is a medium tall shrub with blue-green stems that produce clusters of golden yellow flowers from September throughout fall, very showy in the landscape. Matted hairs on thin leaves cast a silvery appearance. Native throughout the southwest, in warmer climates it is evergreen. The official name has been changed to Ericamera nauseosa, but is still referred to as Chrysothamnus (meaning golden bush). Seeds prolifically -- is a good pass-along plant to friends, neighbors, relatives and passersby.

Common Name: Trumpet Vine, Trumpet Creeper

People either love trumpet creeper or hate it. The first three years, I couldn't wait for it to mature, filling with red-orange trumpet shaped flowers. It seems I've spent the next 20 years trying to kill it. Trumpet vine will die, but only for those who want it to live. If a gardener gives it the death wish, it will be sure to flourish. Native to most of the eastern half of the U.S., it is low water-use, thrives in heat. Must be in a sunny location to bloom profusely. Considered to be invasive, especially when over watered. Not particular about its soil.

Common Name: Victoria Blue Salvia, Mealycup sage

Victoria blue salvia is usually not cold hardy in the Texas Panhandle, but every once in awhile, one will winter over. But that shouldn't stop you from replanting this lovely, summer long blooming native to regions further south, classified by some to be one of the top ten flowers for Texas gardens. Upright and dense flower stalks in blue, white (Alba) and deep blue or violet. Salvia farinacea continues to be hybridized to create new introductions. Often referred to as mealycup sage, its stately appearance deserves the nobler moniker, Victoria Blue.

Common Name: Illinois Bundleflower

Illinois bundleflower should be grown for its unusual characteristics of seedpods and leaves, if nothing else. A member of the legume or bean family, the seed pods turn dark brown, leathery and twisted in appearance and rattle in the wind in late fall. The compound, alternate, pinnate leaves fold when touched or when exposed to strong sunlight. Small white flowers in summer. Attracts butterflies, birds love its seeds. The plant can grow to be quite large if in high water-use areas.

Common Name: Sotol, Desert Spoon

Dasylirion is one of the plants I call a southwest evergreen. Different in appearance from traditional evergreen shrubs, it fulfills the same purpose in native and xeric landscapes. Symmetrical rosette of narrow leaf blades or leaves emanating from the center of the rosette. Barbs lining the margins of the thick pale green leaves give Dasylirion another common name, sawtooth yucca. As Sotol ages, a trunk may form under the rosette and even multiple heads may develop. At maturity, an 8-10 foot tall flower spike ascends from the center where thousands of small creamy white flowers open.

Common Name: Rose mallow, Texas Star

Two southern native hibiscus suitable for the medium to high water-use garden. Large green leaves are superseeded by very large and showy flowers. H. moscheutos  is cold hardy and has some of the largest flowers, up to a foot across in red, rose and white, usually with a red eye. H. coccineus blooms scarlet 3 inch flowers -- not cold hardy but worth trying as a specimen container plant.

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