Plants that will live in areas that experience 90-120 heat days (AHS Heat Zone 8) 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.
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.
A terrific variety for the prairie garden, though requiring prairie conditions -- good soil with good drainage and more frequent watering than our native, E. angustifolia. Coneflowers are all the rage right now with many new introductions every year, ranging from white, yellow, orange to the popular purple. Most of these should be located in your medium to high water-use area. The richer the soil and with weekly watering (high), you'll enjoy grander blooms. A good border plant in the transition area between turf and medium water-use. E.
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.
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.
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’.
Veronica x ‘Blue Reflection’ should be an indispensable evergreen groundcover for you, as it has become for me.
Rarely does a shrub feature as much versatility as the blue mist spirea. It will grow and flower in sun or shade, low water-use or high. This Caryopteris, a hybrid itself, normally blooms in a pleasant light blue, but other selections have deeper blues hues. Summer blooming into fall. And as unlikely at it seems for hybrid to set viable seed, blue mist spirea reproduces itself pleasantly, never invasively. Indeed, any little volunteers are welcome.
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.
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.
Buffalograss is North America's only native turfgrass, grows well in clay soils. A warm season grass that spreads by stolons, it is our best selection for low water-use lawns. It will survive very nicely on 15-20 inches of annual precipitation. For green turf summer long, a once a month watering is all that is needed. The common species is short to 4-8 inches, light gray/green to blue/green and goes dormant in fall, greening up again in May. Many newer varieties are being developed for wider blades and deeper green colors, such as Legacy® and Turffalo®.
Junipers are native to much of the U.S. and come in many sizes and shapes. Juniperus horizontalis is the low growing and spreading juniper, used mainly as an evergreen groundcover. There are many varieties available, one or more to suit every purpose and location. Colors and heights vary from the common dark green evergreen to blue green, blue and even lime or chartruese. Their hallmark is their fine texture, many of the newer varieties have a pleasant soft touch. Water use can vary as well, but typically, once established many will thrive on once a month deep watering.
Gayfeather is one of the High Plains jewels of autumn, sending up grasslike leaves or stalks that bloom gloriously in September and October to fuzzy purple spikes. At maturity, one plant can grow a dozen or more, size and number depending on rainfall amounts. Drier years, the stalks are few and short, but with monthly or twice a month watering, the plant displays much more vitality. The purple flowers contrast nicely with the many yellow flowers that bloom on the plains. Liatris punctata is the most drought tolerant of the genus.
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.
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.
This pink (old common name referring to the pinked edges) is pink. Heat tolerant fragrant perennial forms a spreading mound. The buds provide interest for several weeks before they open. Other perennial dianthus thrive in our area, biennial and annual dianthus as well. Look for heat tolerant varieties. D. gratianopolitanus ‘Firewitch’ is another dianthus to try. Carnations, maiden pinks, Sweet Williams are members of this genus. There are many hybrid cultivars, and more every year.
Another old garden perennial that’s still good for our Panhandle cottage gardens, Physotegia virginiana is native to eastern and southeastern US. A terrific addition to the late summer and fall garden. Comes in three pleasing colors of light pink, purplish pink and a real pretty white. The white variety "Miss Manners' and 'Summer Snow' are both better mannered, not spreading quite as vigorously. It's native habitat is in moist, rich soils, but keeping it on the lean side makes it more "obedient".
Yuccas for Texas High Plains Landscapes
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.
Summer flowering low water-use native tree, several varieties to choose from. Willow like green leaves. Cold hardy reliably in Zone 7, will winter over most years in Zone 6. The variety pictured in the close-up flower photo is "Lucrecia Hamilton", the variety in the third photo is 'Art's Seedless'. During early autumn snows, be quick to shake snow off the branches to avoid breakage.
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.
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.
Sand lovegrass is a warm season bunch grass typically found in sandy soils east of the Rockies over a wide range of the U.S. The grass clumps themselves are usually 12-18" tall with the plumes rising to 3-4 feet. Will grow in clay and poorer soils. Very pleasing wispy, arching habit with a soft sway and rustle in the wind. Can grow in partial shade. Seed heads are somewhat purple, fine textured. Will reseed. Low or no water-use.
One-seed juniper is the juniper found in the dry hills and mesas throughout our area and the Southwest in elevations from 3500 to 8000'. Slow growing on top, it's tap root grows quickly and deeply, making them very difficult to transplant. It's habit is shrubby with several stems and branches growing low to the ground, making it a good habitat plant. Extremely drought, heat and cold tolerant.
Showy evening primrose is a plains states native, including the Texas Panhandle. Showy evening primrose blooms whitish pink in late spring, with each flower lasting a single day, opening in the morning and closing later in the day. The leaves are green narrow and lance-like and emerge from spreading rhizomes. The plant spreads prolifically by rhizomes and seeds, especially in amended and well watered soil. It is not well mannered in a mixed bed or border, I consider it invasive for the garden.
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.