Vines possess considerable charm. They can integrate human-made structures into their natural surroundings, conceal eyesores, and contribute to yard privacy. Vine flowers, often in splendid profusion, can surprise us at eye level or entice us to look up in wonder when they arch over our heads. It is remarkable, too, that so many high-performing and low-maintenance vines can be easily acquired without any financial cost.
Wild honeysuckle is a popular find. It grows rapidly, covers a wide area, requires little horticultural attention, and maintains its leaves all year in most regions of Texas. But not all varieties of honeysuckle are equal. Consider Japanese honeysuckle (Lonicera japonica) with its bee-loving and crowd-pleasing abundance of fragrant, creamy, sometimes purple-tinged blooms. This plant is commonly sold in local nurseries but it is also available, free of charge, in both cultivated or wild landscapes seeded by fruit-eating birds. However, the showy beauty of Japanese honeysuckle disguises its less well-known features, including its extreme survival-of-the-fittest aggression when annexing territory and fatally blanketing its defenseless neighbors.
In a small backyard experiment I planted both Japanese honeysuckle and coral honeysuckle (L. sempervirens) within 10 feet of each other along a fence. I had propagated both plants from gratis field cuttings. The coral honeysuckle (also known as woodbine) had "court advantage," as it were, because it was a Texas native and was positioned a little more northward on the fence. Such positioning meant that the Japanese honeysuckle, following the angle of the sun for much of the year, might be more inclined to grow southward, away from the coral honeysuckle. It did indeed grow more to the south than to the north, but within three years it had also completely overwhelmed the coral honeysuckle, which by then had barely managed to expose nearly fifteen precious blossoms from within the stifling leafy dome of its militant competitor.
Few plants can, like ashe junipers and certain cedars, repel the rapacious tendrils of Japanese honeysuckle. So one needs to think twice—maybe three times—before planting this vine in a yard.
I intervened, of course, and saved the coral honeysuckle. Now its trailing red trumpets, with orange interiors, bloom frequently throughout the year and are a favorite of skittish migrating ruby-throated hummingbirds. Coral honeysuckle, which is found wild especially in the eastern half of Texas but which will thrive non-invasively in cultivated sites throughout the state, frequently puts on a double show in winter. Then its enduring leaves may turn a soft scarlet to complement bright orange-red berries still clinging to the vine. And if the winter season is unusually warm, there will also be blossoms, sometimes even on New Year's Eve.
Another hummingbird favorite, free for the taking, is the trumpet creeper (Campsis radicans), a native catalpa vine especially prevalent in the eastern half of Texas but also readily adaptable elsewhere in the state. Sometimes entire telephone poles disappear beneath this vine's marvelous tower of orange tubular flowers. Utility company objections are to no avail. For the trumpet vine, it sometimes seems, the sky is the limit.
This plant, a family relative of the less ambitious, moisture-loving native cross vine (Bignonia capreolata), climbs by means of aerial roots and has a long May-to-September blooming season. It produces an abundance of leathery pods with winged seeds, but mainly spreads by producing new plants from underground runners.
I appropriated one of these complimentary sucker shoots from a construction site, planted it in a sunny edge of my yard, and one day it matured into a 20-foot lattice of tangerine flowers swaying gently in the warm breeze. Greedy for even more blossoms—after all, more is better, right?—I fertilized its roots. That was hardly my wisest decision, for the plant grew higher with more leaves but also produced considerably fewer blossoms. One of the advantages of native plants, so well-adapted to their habitats, is that they require little assistance from us. This is certainly the case with the trumpet creeper, which does better with less rather than more nitrogen in sand, loam or clay soils. At least I did not have to trim its roots to restore its display the following year. I simply neglected it, and in return it rewarded me with copious blossoms.
As with the high-climbing, delicate Virginia creepers found in Texas, there have been reports of skin irritations from the trumpet vine, though my intimacy with it has never resulted in a rash of any kind. Its aerial roots will damage bricks and shingles. While not as aggressive as Japanese honeysuckle tendrils, trumpet creeper runners can be invasive and may require simple cutting or mowing to keep them under control—a small consideration compared to the free gift of such a high-performing, low-maintenance plant.
Passionflowers are long-standing Texas favorites (see TEXAS GARDENER, March/April 2000), but like honeysuckle varieties, they are not equal.
The popular, smaller-flowered Passiflora foetida is treated as a native of the Valley, but (as Christina Mild has observed) it is a cultivar whose flower-laden, rapidly growing vine soon smothers its more pacific neighbors. For a more moderate vine there is the maypop passionflower (Passiflora incarnata), an East Texas native which is easily propagated from a cutting. The more easygoing maypop passion flower, which tends to die back to the crown each winter and to send up new shoots each spring, does not require a large amount of space. Nevertheless, it produces lush lavender blooms between May and August. The maypop requires sandy loam or other well-draining soil, and enjoys dappled light. It is inclined to trail along the ground unless it receives a little assistance at first in locating a support for its tendrils.
Far more control is necessary for purple bindweed (Ipomoea trichocarpa), a rosy-lavender morning glory that relishes garden beds and other disturbed ground. A pretty family relative of the coarser Texas bindweed (Convolvulus equitans), this deep-rooted perennial (sometimes called the sharp-pod morning glory or the common morning glory) just shows up gratuitously in all areas of the state except (according to several books) the Far West and Panhandle. For many gardeners, this plant is a nuisance that can be combated only by manual removal. And it certainly lives up (or down) to its bindweed name. This morning glory will strangle other plants. I have observed its vines positioned precisely across the nodes of some nearby bushes, which during the following spring were unable to sprout leaves from those tightly encircled sites until I carefully freed them.
Although it is ornery, this rapidly twining, profusely flowering vine has contributed to the beauty of my gardens from April to November. With modest weekly monitoring, to keep it on track and out of bordering plants, it has grown superbly on various wire supports of several feet in height. Passers-by are struck by its beautiful tapestry of lavender funnels. They hardly suspect the darker side of this plant because it seems so beautifully well-behaved in my garden.
I do not recommend the introduction of purple bindweed into a garden, only its management to your advantage if it capriciously shows up there. In fact, at the end of each flowering season I uproot and destroy the plant, which is too capable of reviving from even small pieces to be a good candidate for composting. During the next season, several new wild morning glories always emerge in my garden, whether or not I might want them there.
The maypop passion flower, the wild morning glory, the trumpet creeper, and the coral honeysuckle may be vines free for the taking, but their arresting beauty is priceless. As if charmed, they can transmute a low fence or a high wall into a precious horticultural artwork where, like winged sprites, hummingbirds and butterflies keep vigil.