Gardening Articles: Landscaping :: Trees, Shrubs, & Vines
Amazing Annual Vines (page 3 of 4)
by Veronica Fowler
How to Grow Annual Vines
Nearly all annual vines do best if sown directly in the garden a week or two after the average last frost date. They grow so quickly that if started too early indoors they become stressed in their small space and tend to suffer from transplant shock. Also, direct-seeded plants will catch up with their coddled indoor-started counterparts by mid July or so.
You may want to start a few plants of finicky germinators, such as sweet pea, indoors as a backup. That way, if Mother Nature supplies too little or too much rain, or too little or too much heat, for proper germination, the indoor seedlings can come to the rescue. Start indoors on the last average frost date; plant in peat pots or cardboard egg cartons so pot and all can be planted without disturbing the roots. Transplant seedlings once they have their second set of leaves, one to three weeks later.
Annual vines, like so many plants, like full sun and well-drained, good-quality soil. However, if planted in too-rich soil or fertilized with too much nitrogen, they tend to produce excessive foliage and not enough flowers. If you want to fertilize, work a little compost into the soil, or at most an all-purpose fertilizer, such as a 5-10-5, according to label directions. The best time is just as plants begin to bloom.
Keep seeds evenly moist until germination. After that, most vines require average to modest watering despite the heavy demands that all the foliage puts on their root systems. According to Wanda Sorrells, staff horticulturist for the Geo. W. Park Seed Co., "Many annual vines are highly drought tolerant. The only side effect [of too little water] is that they might not grow as big." And many might wilt slightly on a hot afternoon but revive by evening.
It's important to provide support at planting time. Some annual vines, even when planted just 3 inches away from the support, will spend days slowly whirling around, reaching blindly for a support in an eerily intelligent way. That time and energy could be put into climbing and developing foliage and flowers. At planting time, if the support can't be placed next to the seed, put a short twig into the ground leading from the seed to the support.
Most vines climb by twining rather than clinging. This twining habit makes them even easier to cultivate. Simply provide a pole or stake and they'll twine right up, though it never hurts to give them a guiding hand every few days until they're a foot or so tall. On a building or other smooth, flat surface, a trellis helps. Construct one of wood, string, or even monofilament fishing line, which creates a nearly invisible support. Unlike perennial vines, even vigorous annual ones (to 20 feet) are fairly lightweight and seldom topple their supports.
The few clingers, such as sweet peas, love-in-a-puff, and purple bell vine, do better with string, netting, mesh, or a trellis for support.
Once these vines are established, few pests or diseases bother them. Their height allows good ventilation, and because they're annuals, diseases seldom overwinter. (Or it may just be that the vines grow so fast they outrun any pests or diseases.) All are killed by hard frost. Simply pull or cut them down and compost the remains. Many are actually very tender perennials and grow year-round in USDA Hardiness Zones 9 and warmer.