In a recent article on friendly privacy, I suggest vines to achieve a softer and more welcoming appearance on privacy screens. But beware: Vines and their support structures need to be well matched. Vines vary dramatically in the amount of space and structural support they need. Here are some of the best annual and perennial vines for zones 5-7 classified by the amount of support they require.
Purple hyacinth bean requires vertical support.
Dutchman's pipe vine provides complete privacy for this porch.
Climbing hydrangea requires a very strong support, such as this stone railing.
The following annual vines provide more flowers than most perennials and require the least amount of structural support: Morning glory (Ipomoea purpurea), morning glory vine (Ipomoea tricolor), and moon flower (Ipomoea alba) grow easily from seed in May to lengths as much as 15' by early August. The first two open their flowers in the morning, moon flower opens at night.
Decorative peas are also good candidates for the "lightweight" category. These include the everlasting pea (Lathyrus grandiflorus), perennial pea (Lathyrus latifolius), and the well known, sweet-scented sweet pea (Lathyrus odoratus). These reach 6' - 10' by mid-summer.
Climbing nasturtium (Trapaeolum majus 'moonlight') produces 6' - 8' of flowers best in nitrogen-poor soil and bright sun. (Nitrogen will cause the plant to produce many leaves and few flowers.) As annuals, all of these will die at the end of the season. You will need to reseed the following year, though morning glories are famous for self-seeding.
Vines that Need Medium Support
Several annuals fall into this category, including the highly decorative scarlet runner bean (Phaseolus coccineus) and flashy purple hyacinth bean (Lablab purpureus). These productive, fast-growing vines can reach a height as much as 20' by midsummer. Scarlet runner bean is sometimes so dense it can form the walls and ceiling of an outdoor room.
Bitter gourd or bitter melon (Momordica charantia) is another source of dense foliage with interesting fruit. Luffa gourds (Luffa acutangula) and ornamental gourds (Cucurbita pepo) and many other types of gourds, including cucumbers and small pumpkins, thrive on vertical structures. For deer resistance and good fall color, the medium-weight Virginia creeper (Parthenocissus quinquefolia) is an excellent choice among perennial vines. Another fast-growing herbaceous perennial vine is the herb golden hops (Humulus lupulus 'aureus'). And no discussion of perennial vines would be complete without mention of native Virginsbower (Clematis virginiana) and the many clematis hybrids. Also in this perennial category is honeysuckle (Lonicera sempervirens).
If deer-resistance is your top priority, another selection in the mid-weight group is Firethorn (Pyracanthus spp.). It can make a very interesting trained vine or topiary of 10' or more year round because of its fall colors and berries that persist into winter.
Vines that Need Heavy Lifting
Some vines develop woody trunks and, over a few years, can cover entire pergolas and form the sides and ceilings of outdoor rooms. The challenge with these vines is to provide enough structural support.
Climbing hydrangea (Hydrangea anomala ss. petiolaris) will grow as much as 40'. Climbing roses and rambling roses (Rosa spp.--many varieties) can twine or weave over lattices from 15'-30'. Grapes (Vitis spp.) have been grown on trellises in the northern hemispheres for centuries, but hardy kiwi (Actinidia arguta) is a more recent introduction that will outpace the most vigorous grapes in their vining capabilities. Dutchman's pipe (Aristolochia macrophylla) is a native vine that some have used successfully to create outdoor rooms. Wisteria is perhaps the classic woody-stemmed flowering vine, though some wisteria species are now labeled "invasive" by the USDA Natural Resources Conservation Service, among other organizations.
Each of these requires a trellis or fence of considerable strength that is solidly placed in cement or another strong footing.
Vines and trellises can be a very rewarding combination, not only as attractive outdoor decor but also as a source of privacy and a happy place for many beautiful vegetables and flowers. To have the best success, match the support needs of the vine with the fence or trellis structures in your landscape.
Here are two books with pictures, ideas, and instructions:
Climbing Gardens: Adding Height and Structure to Your Garden, Joan Clifton, Firefly Books, 2003
Vertical Vegetables and Fruit, Rhonda Massingham Hart, Storey Publishing, 2011