UNITED STATES—Boston ivy and creeping fig are good aggressive vines for freeway overpasses and sound-walls. They are resilient to harsh exposures and pollution, and help to muffle the sound of traffic. Boston ivy provides remarkable foliar color in autumn before defoliating in winter. Creeping fig provides thick evergreen foliage that overwhelms any graffiti that it can reach.
However, their aggressive behavior that is such an advantage on freeways is precisely why they are not so practical for home gardens. Boston ivy gets around so efficiently because it grabs onto surfaces with ‘holdfast disks’ (modified tendrils) that damage paint, stucco, wood and just about anything that is not built like a freeway. Creeping fig is at least as destructive with clinging aerial roots, as well as constrictive stems that can crush smaller plants, fences and anything else that it might grab hold of.
Most vines are aggressive in nature. They exploit trees for support, and then compete with them for space. Some are complaisant enough to mingle relatively peacefully with the trees that support them. Less honorable vines have no problem overwhelming the canopies of their supportive trees. Creeping fig and other related figs are known as ‘strangler figs’ because their constrictive roots and stems crush and kill the same trees that help them get above the forest canopy.
Such behavior needs to be considered when selecting vines for home gardens. Bulky and potentially constrictive wisteria vines that would tear lattice apart can be quite appealing on sturdy arbors or trellises. Lattice could instead be adorned with docile Carolina jessamine, lilac vine, mandevilla or even regularly pruned passion vine. Star jasmine and the various trumpet vines work nicely to obscure chain link fences. With regular selective pruning, pink jasmine, honeysuckle and potato vine work well on rail fences.
Climbing roses and bougainvillea do not climb on their own, but can be trained almost like vines. Some varieties stay small enough for low fences and trellises. Larger types are proportionate to larger fences and arbors.
Highlight: Red Passion Flower Vine
Compared to the common passion flower, the three inch wide red passion flower, Passiflora manicata, is more colorful with cherry red flowers, but does not so prominently display the weirdly distended floral parts that passion flowers are known for. Bloom is not as profuse either, particularly among vigorous vines.
However, red passion flower vine has the advantages of somewhat more resilient and greener foliage, and sturdier vines that can climb almost to thirty feet high. It grows so vigorously that it can be surprisingly overwhelming, even if pruned severely or cut to the ground at the end of each winter. It is not so rampant in light shade.
Copies (new vines) are easy to propagate by layering, which involves merely burying a section of vine while still attached to the parent vine until it develops enough roots to be separated. The buried section should be at least a few inches long. At least a few inches of the tip of the vine should extend beyond the buried section.
The fruit of red passion flower vine is considered to be toxic, but often gets eaten anyway. Fortunately, fruit rarely develops.
By Tony Tomeo