If you are looking for an interesting way to add structural elements to your garden consider a pleached hedge, tunnel or arch. Pleaching is method of pruning and weaving branches together for ornamental purposes. It's similar to topiary, but more structural.
For example, deciduous trees are planted in a line close enough together that the branches will eventually meet and interweave to form a wall or ceiling of foliage. There is some pruning and training involved, but the plants do most of the work.
Pleaching is an ancient tradition dating back to the Romans. One of my favorite examples is the Pleached Lime Avenue leading up to the entrance at Arley Hall. Planted in the 1850s the trees form "a giant hedge on stilts" on either side of the drive.
I used a similar device on a smaller scale for a client to create a privacy screen in a garden that shared a low brick wall with the neighboring patio. We planted a row of camellias closely together and "legged up" the trunks to about the top of the wall. Then the top branches grew together into a screen.
If you would like to try the technique, this pleached arch is a great way to get your toes wet. I installed this arch over the entry gate to my heel yard with great results. It's a fairly simple project; you just need to be persistent in shaping the trees as they grow.
- 2 or 4 trees depending on the available space, purchase size depends on your patience
- Soil amendments for planting
- Simple arch template
- Jute twine
Build and paint the arch template. Choose a paint color that blends in with the branches.
Attach the arch template to existing gate posts. If none are available, install a pair of fence posts to hold the template aloft. Keep in mind that you will want to remove the posts eventually.
Plant a deciduous tree of your choice on either side of the entryway. If you are creating a new entry, an opening of 4 to 5 feet is a comfortable width and yet close enough to pleach the branches of your trees. If space allows, a pair of trees on either side of the gate is even better. Read more about tree planting.
If necessary, clear the trunks of branches up to about waist or shoulder height so they are all even.
Allow branches closest to the entry to grow long enough that you can attach them to the template. This may take several growing seasons. Keep the opposite side sheared.
Tie the branches to the template with jute or sisal twine.
As the trees grow, continue to tie and prune to shape.
Once the tree canopies reach the desired height and depth, shear the tops and sides flat.
About the only maintenance is a trim in early summer and again in autumn after the leaves fall to give the bare branches a tidy appearance through winter.
Trees for Pleaching:
- Apple (Malus domestica)
- Pear (Pyrus spp.)
- Hornbeam (Carpinus betulus)
- Lime or linden (Tilia x europaea)
- European Beech (Fagus sylvatica)
Not being very skilled with a hammer and saw I enlisted the help of a friend to build a template for the arch. He created a 5 foot tall grid made up of 6' x 6' squares that was wide enough to span the opening of the existing gate. He used 3/4" square wood for the body of the trellis and a flexible wood strip to finish off the shape of the arched opening.
I planted the trees and installed the arch about 6 years ago. This year the trees are about 12 feet tall and the branches are just starting to weave together nicely.
I used hornbeams, Carpinus betulus, for this project. They have a nice dark green summer leaf that turns golden yellow in fall. They grow best in full sun locations and are cold hardy in zones 4 ? 8 and heat tolerant in zones 8 through 3.
My hornbeams are planted 4 feet apart, 2 feet away from the fence line and 2 feet out from the gate posts.
If you are exceptionally gifted you can skip the wooden grid. Create a template by simply tying jute twine in parallel lines from one tree to the other. Train the branches to grow following the jute. As the tree grows, carve out an arch over the entry.
Choose trees that have strong and pliable branches. Avoid fast growers that are short lived such as willows.