By William J. Scheick
any of the most popular plants in Texas gardens originate from south of our border. For an impression of just how many, simply preface the word "Mexican" to bush sage, feathergrass, heather, petunia, sunflower, oregano, orange blossom, and firebush. And don’t overlook cigar flower, bird of paradise, and yellow bells – each, as well, from Mexico.
Given their native habitats, such plants tend to fare best in the southern parts of our state. Many do well in zone 8, where they usually require some protective measures during winter if they are to be grown as perennials rather than annuals. Four of the five plants profiled here make first-rate container selections throughout Texas. During the winter they can be brought indoors or placed in a greenhouse, where they will continue to flourish until it is safe again to bring them outside.
Queen’s wreath (Antigonon leptopus), a buckwheat-family member also known as coral vine and queen’s crown, is a fast-growing Mexican plant that has become a prominent Lone Star resident. This tuberous perennial bears delicate heart-shaped leaves and copious lacey clusters of hanging radiant pink or white flowers throughout summer and autumn. Virtually pest-free, except for enthralled bees, it thrives in heat and withstands droughts in zones 8-9. In fact, too much water will impede blooming. Perfect for sunny fences or arbors in well-drained sites, this easily-grown tendriled tropical can reach up to 30 feet and can become territorially aggressive – which is why it appears on the Florida watch-list of plants that might threaten native flora. So keep this butterfly favorite far from other plants that it might overrun. Coral vine dies to the ground with the first frost, and in most parts of Texas its freeze-vulnerable tubers need a thick blanket of winter mulch.
For home foundations, garden beds or containers try Mexican honeysuckle (Justicia spicigera). Also sold as firecracker plant or desert honeysuckle, this small shrub bears small but profuse orange tubular flowers for nine months provided it receives part shade and adequate water. A hummingbird attraction, Mexican honeysuckle dies back at 25 degrees Fahrenheit, and its roots (which spread underground) should be safeguarded from hard freezes. Light winter pruning of woody stems enhances the plant’s rapid resprouting each spring, and pinching back fosters a fuller look. While this desert perennial is not fussy about soil and prospers in xeriscapes, it is susceptible to growth-stunting chlorosis, an iron-deficiency signaled when leaves turn yellow while leaf-veins remain green.
Mexican Bush Marigold
Bright, yellow flowers distinguish Mexican bush marigold (Tagetes lemmonii), a three-foot perennial also marketed as Copper Canyon daisy and Mt. Lemmon marigold. This water-thrifty south-of-the-border native, which also runs into southern Arizona, bears deer-resistant aromatic leaves. It blooms in cycles from early spring through first frost, when it dies to the ground. A fast-growing relative of Mexican mint marigold (T. lucida), the Copper Canyon daisy is a great autumn showoff in draining locations as far north as zone 7. Expect butterflies by the legion.
Summer snapdragon (Angelonia angustifolia), another striking Mexican perennial, sports leaves smelling like apples and 18-inch spikes flowering periodically throughout the summer. In most of Texas, sun-loving Angelonia, or angel flower, is best managed as a container plant because it is not winter hardy above zone 9 and requires watering whenever its well-drained, organically-rich soil dries. A container also restricts this plant’s slight tendency to sprawl.
Available in purple, blue, pink, white and bi-colored striped varieties, summer snapdragon looks splendid in window-boxes sheltered by afternoon shade.
Also ideal for container gardening is Salvia chiapensis, a shade-loving two-foot sage from Chiapas, Mexico. Its dazzling fuchsia-colored blooms ornament every season if the plant is situated in fast-draining sandy soil, watered deeply on a regular basis, provided with dappled sunlight or at least afternoon shade, protected from snails and sheltered from temperatures below 32 degrees Fahrenheit. This perennial blooms prolifically, even while wintering in a greenhouse.
Because of its cloud-forest origin, where its leaves enjoy frequent misting, Chiapas sage can be finicky. But as veteran gardeners know, sometimes beauty requires pampering.