Annual Flowering Vines

Frank Lloyd Wright

Vines have a magical or mystical charm. Their rapid growth and twining habit makes them intriguing and fun to grow.

There are several uses of vines in the garden. Vines give character to garden and landscape features. They add a vertical dimension to a garden or landscape. The attractive foliage and flowers on vines add texture and color to otherwise long, monotonous walls and fences. Vines can hide or camouflage less attractive areas in the yard and provide a screen for patio or private garden areas. Fences, posts, and utility poles appear more natural and less dominant if covered with flowering vines.

Annual flowering vines provide a quick, yet temporary cover for garden structures. Even in Iowa's short growing season, many annual vines will cover a trellis or a mailbox post with multitudes of flowers. They are easy to grow and relatively free of pest problems. Below is a list of annual vines that can be grown successfully in Iowa.

Cup- and- saucer vine (Cobaea scandens) is a dense vine that can grow 15 to 25 feet in one summer. It will grow rapidly over a fence, trellis, or wall. Its stems cling by branched tendrils that grow on the end of each leaf stalk. The vine bears unique flowers about 2 inches long and 1 1/2 inches wide from early summer to mid-fall,. The flowers resemble tiny greenish-purple, lavender or violet cups sitting on green saucer-like bases. The cup-and-saucer vine thrives in full sun and in a moist, well-drained soil. Sow the seeds after the threat of frost is past, later thinning the plants to about 18 to 24 inches apart.

The Hyacinth bean (Lablab purpureus) vine grows 10 to 30 feet in a single summer and will completely cover a fence or trellis with its twining stems. It has large, 6-inch green leaves with burgundy veins. Its stems are also burgundy. The hyacinth bean bears clusters of purple or white flowers in midsummer through fall. The flowers are followed by flat, burgundy-colored pods. The hyacinth bean requires full sun and well-drained soil. In early May, plant the seeds about 1/2 inch deep near the trellis or support. Soak the seeds in warm water a day or two before planting.

The hyacinth beans pods are edible when harvested young and tender. However, the purple-colored pods fade when cooked.

The morning glory family is a large group of annual vines. They grow best in full sun or partial shade. To hasten seed germination, nick the seed coat with a file or soak the seeds overnight in warm water before planting. They can be direct-seeded or started indoors 4 to 6 weeks before planting outdoors. Set the plants in the garden after the threat of frost is past.

Morning glories (Ipomoea purpurea) grow so fast that you can almost see the vines stretching and twining up the trellis or post. The vines will reach 10 feet just two months after planting. They bloom in shades of purple, blue, pink or white with a lighter-colored tubes. A new variety, 'Tie Dye', introduced by Park Seeds, produces sky blue flowers that are mottled with navy blue stripes and swirls. The trumpet-shaped flowers on morning glories appear in mid-summer and open in the morning and often close in the afternoon. On cloudy days the flowers remain open during the day.

Like morning glories, moonflowers (Ipomoea alba) also grow very rapidly. They have prickly stems that can grow up to 40 feet in one season. The large, oval-to heart-shaped leaves surround large, fragrant white flowers. These flowers resemble morning glories, however, they are somewhat larger and open at night and close in mid-morning.

Cardinal climber (Ipomoea multifida) will grow 10 feet or more. The twining stems have small, dainty palm-like leaves. It produces 2-inch red flowers with white centers. The cardinal climber blooms throughout the summer. Direct sow the seeds near the support structure or start the seeds indoors 6 weeks before transplanting. Plant after the threat of frost is past.

Sweet peas (Lathyrus odoratus) are grown for their fragrant flowers. They grow rapidly up to 6 feet tall. The flowers appear in early summer in colors from blue and lavender through salmon and red. The tendrils on a sweet pea will easily climb and cling to a light-weight trellis or fence. Soak the seeds overnight in warm water prior to seeding. Sow the seeds in the garden as soon as the soil can be worked.

The twining stems of scarlet runner beans (Phaseolus coccineus) will climb 10 to 20 feet. The bright green leaves are a beautiful contrast to the profuse sprays of flaming red, pea-like flowers. They should be planted in early May in a protected, sunny location. The pods that form after the flowers fade may grow to a foot long. If left on the vine, the pods will turn black, mottled with purple. Scarlet runner bean pods are tasty if they are harvested when only 2 to 3 inches long. The flowers are also edible and can be used to garnish soups and salads.

Black-eyed Susan vines (Thunbergia alata) produce dainty, funnel-shaped flowers that vary in color from white to yellow to orange. The dark-colored throat gives the flower it's "black eye". The twining vines will grow 3 to 6 feet tall. Since they do not like intense heat, they perform best in locations that provide partial or light shade. The best flower display on black-eyed Susan vines occurs in late summer or early fall when the temperatures are cooler. The seeds can be direct-seeded or started indoors 6 to 8 weeks before transplanting. Plant them outdoors after the threat of frost has passed.

Some varieties of nasturtium (Tropaeolum majus) are actually vines that climb up to 10 feet high. The orange, yellow, salmon, pink, white or red flowers that form in mid summer are edible. They add bright color and a peppery flavor to salads. The coiling leaf stems grow quickly and can be trained on trellises or posts. Plant them in a sunny, well-drained location. The seeds can be sown indoors about 6 weeks before planting outdoors or direct-seeded after the danger of frost has passed.

This article originally appeared in the March 28, 1997 issue, pp. 31-32.