Summer-flowering vines can provide color, fragrance and interest to Louisiana landscapes. They can also provide screening and even shade if they are allowed to cover an overhead structure. Indeed, no other group of plants can provide the same effects as vines.
The following perennial vines are great choices for Louisiana, and will thrive even during the blistering heat of our summer. They are best planted in full to part sun.
The delicate sprays of small, rosy pink flowers that adorn Rose of Montana (Antigonon leptopus, also called Rosa de Montana and coral vine) are unique and delightful. Flowering may occur during summer but is generally most abundant in late summer and fall. This twining native of Mexico goes dormant during winter but reliably grows rapidly from its roots in spring.
Coral honeysuckle (Lonicera sempervirens), a native vine, is remarkably well behaved as vines go. The tubular coral red flowers are produced in clusters at the ends of shoots that often dangle gracefully from this twining vine. The evergreen foliage is a distinctive blue-green with silvery undersides. Flower production is generally heaviest in early summer but continues throughout the season. The flowers are irresistible to hummingbirds. The well-known Hall’s Japanese honeysuckle (Lonicera japonica Halliana) is far more rampant in its growth and is no longer recommended due to its invasive nature.
Chinese wisteria (Wisteria sinensis) is a beautiful – but so very rampant – deciduous spring-flowering vine. For the summer garden we have evergreen wisteria (Millettia reticulata). With its dark green shiny foliage and very intense deep purple flowers, the resemblance to Chinese wisteria is superficial but noticeable. This twining vine is less unruly than Chinese wisteria but is still best used in situations that provide it with plenty of room to grow.
Fast-growing evergreen vines are always useful for covering arches, arbors and pergolas. And akebia (Akebia quinata) is an outstanding twining choice for any of those purposes. The slightly glossy five-part leaves are dark green and provide a beautiful background for the clusters of dusky purple flowers. They are most numerous in April and May but continue to appear all summer. The sweet fragrance they produce permeates the air around the vine but is not overpowering.
Alice DuPont mandevilla produces large, rosy pink flowers in showy clusters all summer long. This tropical vine is generally not hardy planted into the ground, but it is not expensive and is readily available and could be treated as an annual. This is a great twining vine for small areas because it is not as exuberant in its growth as many vines. New colors from dark red to blush pink to white are now available. Although the flowers tend to be smaller than Alice DuPont, the plants grow just as vigorously and produce flowers all summer.
Passion vines provide some of the most beautiful and exotic flowers in the summer garden. The native maypop (Passiflora incarnata) produces delicate lavender flowers followed by edible green fruit. Tropical species, such as the vigorous red passion vine (Passiflora coccinea and P. vitifolia) and blue passion vine (P. caerulea), are just a few of the many wonderful choices in this genus of twining vines. The passion vine is the larval food plant of the beautiful gulf fritillary butterfly and is often planted for that reason. If you see orange caterpillars with black spines eating your vine, consider not spraying.
Other great annual vines bloom in the summer garden. These vines generally live for only one season and must be replanted from seeds each spring.
I would not be without the hyacinth bean (Dolichos lablab). Purple stems hold purple-tinted, three-part leaves and long spikes of lavender and purple flowers. The flowers are followed by shiny, purple bean pods.
Two vines related to each other and similar in appearance are the cypress vine (Ipomoea quamoclit) and cardinal vine (Ipomoea multifida). Their delicate foliage and brilliant red, star-shaped flowers are welcome throughout the garden. I like to let these delicate twining vines weave themselves among other plants and climb up small trees and trellises. Their prolific seed production will be noticed the next year when volunteers sprout up in abundance. Pull up the extras and let the others grow where you want them.
Although related, the moon flower (Ipomoea alba) is quite different. The queen of the evening garden, the moon flower rapidly unfurls large, fragrant, snow white flowers at dusk. The large, heart-shaped leaves form a wonderful background. This traditional vine grows luxuriantly in the sultry Louisiana summer and is perfect planted by a patio or in a container on a balcony.
These vines are only a few of the many that will delight you with their brilliant flowers and long blooming season. Just remember, vines, bless their hearts, have no self-control. Be prepared to control and guide their enthusiasm when you invite these charming plants into your garden.
Dan Gill is a horticulturist with the LSU AgCenter. He can be reached at DGill@agcenter.lsu.edu