Richard Bogren | 7/17/2017 12:44:10 PM
By Dan Gill
LSU AgCenter Horticulturist
(07/14/17) No other group of plants can be used to create the effects that vines do in the landscape. They can soften and link architectural structures such as pergolas, arbors, buildings, fences and arches to the gardens around them. Vines can be used to provide shade, privacy, flowers, ground covers, edible or attractive fruit, fragrance and food for wildlife. It would be hard to imagine a well-planted landscape without the use of vines somewhere.
Vines climb in two distinct ways: by twining and by clinging. Twining vines climb by wrapping their stems, leaves or tendrils around a support. They must have string, wire, latticework, trellises, thin poles or other support structures to twist around.
Clinging vines attach themselves to flat surfaces using aerial roots growing from their stems or special structures called holdfasts. They are useful for covering the sides of buildings or walls without having to build a support. It is important to know how a vine you intend to grow climbs.
Because vines don’t have to put the huge amount of effort and energy it takes to produce a strong stem to hold the plant upright, what do they do with all that energy? They grow. Vines are among the fastest-growing plants in our landscapes. And they have no self control whatsoever.
You must keep this in mind when considering using vines in the landscape. Some, such as wisteria, are downright rampant and should not be used unless the gardener is willing to do what it takes to manage the vine. But even vines not considered so vigorous generally need regular and early training to achieve the effects we want and to maintain them over time.
When it comes to training vines, many gardeners do not realize how important it is to direct how the vine grows from the time it is planted and through its life in the garden. How the vine is trained depends on how it climbs — clinging or twining — and what the gardener is trying to accomplish.
An important characteristic in how vines grow is that they want to grow straight up and get as tall as possible as quickly as possible. In nature, the quicker and higher a vine grows, the sooner it reaches more light. This characteristic is linked to how well they can compete and survive in nature. Sometimes a gardener will take advantage of and encourage this characteristic. When training a vine on an arbor, it is desirable for the vine to rapidly reach the top and grow over the structure to provide shade below.
But in many other situations, this characteristic must be modified. When training a vine on a fence, trellis or lattice panel, it is often desirable for the vine to be lush and full from the ground up. Many gardeners training a vine on a trellis are dismayed to find over the years that the vine is all up at the top and there is nothing but ugly, bare stems on the lower part of the plant. Once that has occurred, there is little you can do to effectively correct the situation. You must prevent it by training the vine from an early stage.
Take the example of the vine planted at the base of a lattice panel. Once in the ground, the vine will rapidly begin to grow straight up the lattice panel until it reaches the top. As it continues to grow, the typical gardener will simply start to prune back the excessive growth at the top. This, in turn, creates a full, bushy, top-heavy vine and leaves the lower portion of the lattice panel with little or no attractive foliage.
To prevent this from happening, start training the vine as soon as it is planted. Weave the existing vine stems horizontally along the bottom portion of the lattice panel. As the vine begins to grow upward, unwrap the vine and force it to grow sideways by weaving it horizontally through the latticework. As you continue to do this over the years, you will create a vine that is full and attractive on the lower part of the lattice panel as well as the upper portion. Once the vine reaches the top of the lattice panel, instead of simply cutting it back take the long stems waving in the air, and bend them around and weave them back down the lattice panel. That will help fill in the top of the lattice panel without creating the thick, bushy top that pruning back would create. Although this example uses a lattice panel, you can apply the same information to vines growing on chain link fences or trellises.
For clinging vines, the approach is different because these vines are clinging to the surface they climb on. When the vine is first planted, it will not be clinging to the support. But as new growth occurs, the vine will grab the surface and start to rapidly grow upward. You cannot pull it from the surface and try to redirect its grow the way we do twining vines, so here’s what you need to do.
Once the vine has attached to the surface, let it grow for 6 to 12 inches, and then pinch the tip. That will encourage the vine to branch out at that point. Once the new shoots have grown a few inches, pinch them, and they will branch out. This will help create a fuller look lower on the surface to be covered. Once again, do not allow the vine to race to the top of the wall as it will want to do. By pinching the growing tips regularly, you delay the vine getting to the top, but you will get a much better coverage in the long run.
If you do a good job of training your vine for the first few years after planting, you will find that it really pays off in the appearance of the vine over time. This is especially important when dealing with perennial vines that will grow in the garden for many years. But the training principles outlined here can also be used on annual vines, such as blue pea vine, cypress vine, morning glory and hyacinth bean.
Twining vines can be trained so they cover the entire area of a trellis. Photo by Rick Bogren/LSU AgCenter
Twining vines that aren't trained leave empty spaces at the bottom of a trellis. Photo by Rick Bogren/LSU AgCenter