Vertical and container gardening also appeal to people with physical disabilities and those who want to spruce up small spaces or add interest to retaining walls and fences.
And plants grown vertically get better air circulation, and seem to develop fewer diseases because leaves aren't lying on the ground in contact with soil-borne organisms, according to the Home and Garden Television Web site at www.hgtv.com.
In addition to these advantages, vertical trellis planting for such vine plants as cucumbers and squash also solves the problem of vegetables rotting due to lying dormant on wet soil, according to the Garden and Hearth Web site at www.gardenandhearth.com.
Simply plant vegetables according to directions, and guide sprouts toward the trellis or other vertical support. Eventually, vines will naturally wrap themselves around the trellis. Support heavier fruits such as melons or large squash with slings made from nylons or other fabric, securing the slings to the trellis, the Web site states.
Adding mulch to the base of container-bound plants can temper the need for frequent watering.
Vertical gardeners can choose from a variety of vegetables, flowering annuals and perennials, and herbs, Semler says. Many plants can be trained to climb vertical structures, and some plant species are meant for growing up rather than out, he says.
Several varieties of tomato, pepper - even cucumber - have been engineered to grow up to a manageable height. Sweet peas and pole beans are perfect for vertical gardens, and "herbs are actually spectacular for it," Semler says.
Hagerstown herbarist Dorry Baird Norris, who writes a weekly column for The Herald-Mail, says such annuals as marjoram, purple basil, hyacinth bean vine, scarlet runner bean, sweet potato vine, lemon gem and tangerine gem marigolds are good bets for vertical and container gardening.
Plants such as clematis, climbing hydrangea, wisteria and grapes can add color and lushness to trellises. Climbing roses also are an attractive addition to vertical gardens, but they must be secured to trellises and other supports. Ivy is a natural for a vertical garden, but the vine's rapid growth must be carefully monitored to make sure it doesn't take over walls and other vertical structures, Semler says.
Arbors, trellises, fence pickets, garden stakes and bamboo canes are just a few of the upright structures that can be used for vertical gardening. And interesting old barrels, tires, bushel baskets, buckets and wash tubs are among many creative container options for growing a wide variety of plants.
"Use your imagination," Semler says. "What works for somebody else might not work for you. Don't limit yourself."