Vines are an amazing group of plants with enough diversity to boggle the mind of any gardener. What binds these wonderful plants together is their universal lack of strong stems. That’s right; vines are lazy plants that rely on some other plant or structure to allow them to grow upwards, or they simply run on the ground.
Because vines don’t have to put effort and energy into producing a strong stem to hold the plant upright, what do you think they do with all of that energy? They grow. Vines are among the fastest-growing plants in our landscapes.
You must keep this in mind when deciding which vines to choose and where to plant them. Some, such as wisteria, are downright rampant and should not be selected unless the gardener is willing to do what it takes to manage the vine. But even vines not considered so vigorous need regular and early training to achieve the effects we want and to maintain them over time.
The well-behaved vine, like the well-behaved child, is created, not born. Gardeners generally don’t realize how important it is to direct a vine’s growth from the time it is planted 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.
Twining vines climb by wrapping their stems, leaves or tendrils around a support, such as string, wire, latticework, trellises, thin poles or other structures they can 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 special support.
It is important to understand that climbing vines want to grow straight up and get as tall as possible as fast as possible. In nature, the faster and higher a vine grows, the sooner it reaches more light. So this characteristic is linked to how well they can compete and survive in nature. Sometimes a gardener will take advantage of this characteristic and encourage it. 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 generally 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 that over the years the vine’s foliage gets concentrated up at the top, with nothing but ugly bare stems on the lower part of the plant. Once that has occurred, you can do little to effectively correct the situation. It is best to prevent it by training the vine properly from an early stage.
As soon as a vine is planted, start weaving the existing vine stems horizontally along the bottom portion of, for instance, a lattice panel. As the vine begins to grow upward, unwrap the vine and force it to grow sideways. Do this by weaving it horizontally back and forth through the latticework, gradually working upwards. Over time you will create a vine that is as full and attractive on the lower part of the lattice panel as it is on 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 panel. That will help fill in the top of the lattice without creating the thick, bushy top that pruning would create. Although this example uses a lattice panel, you can apply the same process to vines growing on chain link fences, trellises or similar structures.
For clinging vines, the approach is different because these vines cling to the surfaces 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 growth 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 off 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 regularly pinching off the growing tips, you delay the vine getting to the top, but you will get 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 vine’s appearance over time. This is especially important when dealing with perennial vines that will grow in the garden for many years. Even though they are only in the garden for one season, also feel free to use the training principles outlined here on twining annual vines, such as blue pea vine, cypress vine, morning glory and hyacinth bean.
Dan Gill is a horticulturist with the LSU AgCenter. He can be reached at DGill@agcenter.lsu.edu