Pleaching: The Special Pruning Technique that Creates Shade
By Kay DiVerde
If you have a path or road on your property, you might want to consider adding shade to it by using a pruning technique called pleaching. Pleaching is a training technique involving weaving branches together. This form of horticultural art includes two rows of trees with the stems from each wall woven over the center to create a green tunnel with shade!
Derived from the French language, plechier (pleach) means to braid. And that’s what this technique involves, braiding or weaving branches together. You can create a shady tunnel over a walkway. You can also close in an area by planting trees around it, clear the branches on the trunks to the desired height of your roof, and then train and weave the branches to create a roof over the area.
Not every tree species will work for pleaching. You need a variety that has branches that are strong and flexible. All of the trees in your pleached rows must be the same variety and species, and similar in size, so growth will be as uniform as possible. Species that work well for pleaching are apple, beech, hornbeam, linden and sycamore. Although any tree that tolerates clippings will work.
When planning your planting for pleaching rows, think how large you plan to let the trees grow (and remember you’ll have to reach the top to do regular pruning). Distances between rows range from three to more than 10 feet. Keep in mind that sunlight will hit rows extending from north to south more evenly than rows going from east to west.
Eventually, your rows of pleached trees will be able to support themselves. In the beginning use a supporting framework to aim the trees’ growth into the form you want. You can build the support out of metal or use wooden crosspieces and posts. You may also use posts with horizontal bamboo canes or wires between them. Posts should be spaced about eight feet apart. Whatever type of support you choose, be sure it will be easy to remove once the weaving is established (don’t dig posts in so deeply that they will damage tree roots upon removal).
When training young trees (three to four years old) for pleaching your goal is to make the branches grow upward and outward. Right after planting cut the young trees back to encourage vigorous growth. A single stem on each plant should be allowed to grow upward. Occasionally, you’ll need to divide growth with a heading cut to cultivate branches, which will encourage it to grow horizontally in one plane.
As the trees begin to grow, tie the main stem and the branches on the side to the support. Allow some branches to temporarily grow low on the trunk, even if you want a length of clear trunk from the ground up to the lowest branches. These temporary branches will help the trunk grow thicker. Remove these temporary branches after a few years when they grow more than a foot long. If you find stems that grow out perpendicular to the plane of the trees, remove them.
You can start to loosely weave branches of adjacent trees together as they begin to reach each other. You may carefully tie these woven branches together. The ties will eventually decay or need to be removed because they may start to strangle the branches.
Over time, your pleached trees will fill in their allotted area. Don’t think your work is done, as these trees will still need annual pruning. Your pruning should include the removal of any stems growing upright near the ground or on the side of branches. You can also thin out growth in areas where it has grown too dense to create a more breezy look. This thinning will also let light get through the branches to avoid the development of dead wood without leaves. You should also remove uncontrollable stems and ones that grow out vertically.
The older the trees get, the stronger the pleached branches will become. The woven branches will naturally graft together. At this point you can carefully remove the framework supports.
Rows of pleached trees can provide welcomed shade to a walking path or sitting area. Take the time to plan the area and direction of pleached trees. Provide the needed support and training while the trees are young. Most of all, be patient. Nothing will happen overnight, but your time and hard work will be well worth the effort!
Kay DiVerde is a freelance writer, horticultural researcher and consultant for Orchard's Edge. DiVerde also writes for a variety of newsletters and publications in the Midwest.
