Fort Collins, Colorado, USDA Zone 5
Who’s native and who is not carries weight in the ever-more-populated state of Colorado, and the least favorite arrivals seem to be Texans. I stay out of this, as I’m a nonnative myself and, worse yet, married to a Texan. Fortunately such attitudes are irrelevant in the garden. Ours is brimming with Texas plants that are much hardier than we might have guessed.
Aside from being terminally greedy for plants and not afraid of killing them, we have good reason to try out plants from Texas. Though rare in Texas, on a long time scale Colorado-style freezes do occur in much of the state. There’s reason to believe some Texas plants, like the beautiful red yucca (Hesperaloe parviflora), which has thrived for more than two decades in Colorado gardens, have evolved a genetic ability to withstand such climatic assaults (rather than just dying and depending on their seed to repopulate the area).
In the past three years we have grown well over 100 native Texan species in our Colorado garden. Many have succumbed to the cold, or grown poorly from lack of heat or their inability to harden off quickly enough in the autumn, but a good number are making themselves right at home, including some that may never have been grown in Colorado before.
Perennial Salvia farinacea ‘Texas Violet’ performs best in dry conditions, attracting butterflies for months. Three oaks are growing vigorously, all with lovely red and orange autumnal hues: Quercus buckleyi, the Texas red oak, grown in Colorado for some time; the lesser-known, finer-textured Q. gravesii; and unusual blue-gray Q. laceyi. Drought-tolerant, bright green papershell pinyon (Pi-nus remota) has been a delight.
Many Texan natives offer much-needed form and structure to the herbaceous mayhem typically found in Colorado gardens. Blue Yucca thompsoniana and hairy Y. constricta are both trunked; turquoise Y. pallida and deep green Y. rupicola are not. Hardy selections of the giant prickly pear cactus Opuntia engelmannii, O. e. var. lindheimeri and O. e. var. engelmannii, have huge pads and are serving as our versions of hedge and foundation plants, while the horse-crippler cactus, Echinocactus texensis, grows into an ever-larger squat barrel. Elegant olive green Dasylirion texanwn and Nolina lindheimeriana have arching evergreen foliage, the former armed with hooked spines, the latter more mild-mannered. The two-foot blue rosettes of our Agave havardiana plants draw constant attention.
For me the most exciting Texan discoveries have been the myriad native ferns. My past 18 years in Colorado have been woefully devoid of ferns, thanks to my sunny, dry, clayey, alkaline gardens. I miss them, cherished plants since childhood stomps in the woods of my native Pennsylvania. Luckily, many of these unlikely Texan ferns accept drought, heat, sunlight, and limey soil. We are trying new ones every year; the two best so far have been Cheikmthes tomentosa and C. horridula.
Colorado mountain townspeople might grumble continuously about loud Texan hikers and skiers, and one can hardly drive Interstate 25 without seeing a green and white “NATIVE” bumper sticker, but in the peacable kingdom of the garden, Colorado plants make good neighbors to our exciting new Texans.
WORTH GROWING: Gladiolus byzantinus
Naturalized in parts of Texas and the Southeast this glad has taken well to our Colorado garden. Large magenta flowers bloom on 15- to 18-inch spikes in early summer. The corms do best in sun and well-drained but not parched soil, preferably clay. Buy only American-grown heirloom G. byzantinus (sometimes called ‘Cruentus’). What is sold as G. byzantinus in the Dutch bulb trade is a runty impostor.