A Guide to Wood Structures in the Garden
WOOD STRUCTURES IN THE GARDEN
By Traven Pelletier
The structure of a garden is not defined only by its annuals, perennials, shrubs and trees, the Architecture and the various built elements designed in or around a garden often provide the strongest elements of the space, and while serving as a backdrop, also define the garden and the space itself. Wooden structures in the garden vary widely and are often some of the easiest and most fun elements to include in your garden or garden design!
In recent years, found and aged elements have enjoyed a resurgence as focal points and it is now fashionable to mix older materials with modern elements. Playful trellises and tuteurs (The commonly used French name for pyramidal style plant trellises) are readily available at most better garden stores, Arbors are often used for garden entrances and pergolas are common elements for creating shade for relaxation and dining space in Gardens. There are wonderful resources online for “Do It Yourself” (D.I.Y.) style projects incorporating simple designs or found elements. One of my favorite projects from perusing home design sites is the easy conversion of a leftover wood pallet into a modern looking vertical garden for annuals, herbs or even a variety of vegetables. By using the slat spaces to create hanging bags, the plants are allowed to establish themselves horizontally and then the pallet is tipped up and secured vertically. I use this as an example mainly because it is such a creative and remarkably unique as well as simple way to reuse a wood element and incorporate it in the garden. My hope in writing this article is to open your mind and encourage your creative spirit to think outside the box in relation to your own garden and creating a design for wood structures and focal points in your garden.
You can use these three main traditional forms as your departure point for more creative wood endeavors:
A trellis is used to support climbing plants and can be fixed to an architectural element or be freestanding in the garden. Often trellises double as “sculptural elements” in the garden and many creative designs have been made with metal that go far beyond what can be accomplished with wood. Many simple designs can be easily made by a homeowner. Use a trellis to create an upright form in a bed of lower plants as a focal point. If you want to get creative and play with the idea of mixing food and flowers, build or buy a tuteur and plant your favorite variety of Pisum Sativum (Common Pea – my favorite is Swiss Giant Snow Pea from Hudson Valley Seed Library) under it; watch as a wonderful fast growing vine appears and then be rewarded with fresh produce in the middle of your annual or perennial bed! Living and edible sculpture await you this year with a trellis!
Arbors form a gate and an arch for your climbing plants to cross a path or mark an entrance or exit to a garden. They are a step up in difficulty as a D.I.Y. project and traditional rounded arbors take quite a bit of skill to create in wood, but straight-topped arbors are a bit simpler. Some nice designs incorporate benches between the two sides in their design. Basic arbors have only two posts, while wider designs have four posts with sides and trellis work between them. Arbors are great for setting off “rooms” in a garden, for hanging gates to integrate with fences, and for creating a heavenly corridor of flowers and scent to walk through when your climber is in blossom! A simple and creative arbor can be built by combining two unique curved branches or trunks from a small tree (fastening them together at the top and digging the bases into the soil at the base). This has a rustic feel and will last a few seasons giving your flowering vine a unique place to expand in your bed!
Pergolas usually have four posts and are large enough to create sitting spaces for a few people underneath them. A variety of designs exist ranging from curved faces and arches to multiple stacked layers of wood slats and or trellis work. All pergola designs are open format so that some light filters through, and depending on what is planted on them, they can become a single mass of vines that creates full shade or be pruned and maintained to create light shade. There are now systems available to install on or under pergolas to protect you and your outdoor furniture from rain and sun with outdoor fabrics. The systems are relatively expensive, but do give more functionality to the space as a true shelter. Adding a pergola to your garden is usually done on a patio space and is a significant investment. Kits or pre-built sets are usually in the thousand dollar plus range, and custom designed installed pergolas often cost several thousand dollars, if not more, for elaborate designs. A pergola will set off a whole area of a garden and make it both inviting and cozier as a space to socialize or relax. The sky is the limit for Pergola designs and I suggest browsing home & garden sites online for ideas before planning one yourself.
Occasionally I am asked what the difference is between a ramada and a pergola. While the term ramada is used less in our region, it is more common in the Southwest, and historically it was a simple roofed structure without walls created for shade during harvest times. Now the term is usually used for a roofed but open structure in the garden, and is sometimes confused with or used as a replacement for pergola, but technically a pergola is an open lattice work design and a ramada is a fully covered roofed design. Both structures usually have posts and at least three open sides. This is the proper place to mention the gazebo, which is a fully roofed and walled structure usually with a door or set of doors that serves as its own fully outdoor room in the garden. The most common gazebo design is an octagonal room, and these have fallen out of fashion over the last decade to be replaced by more open and flexible designs.
Whether you simply create an interesting line and simple trellis in your garden by planting a series of rustic branches or posts, or decide to build a whole outdoor room to enjoy with your friends in your garden, you will not be disappointed by the dynamic that a garden structure brings to your landscape. You can play with the forms that wooden structures bring to your planting beds in many unique ways. The lines of wood will set up framed views and set off the delicate and wildly organic forms of your plantings!
Pressure Treated Wood, usually tagged CCAC, is chemically treated pine or spruce. It is suitable for posts but generally should not be used for trellis work or slats as it warps heavily (this can be overcome in rigid designs with many attachment points). Lifespan ranges from 15 to 25 years.
Cedar (there are quite a few varieties of this material with different price levels) is the most common and most affordable naturally rot resistant wood used in garden structures. It comes kiln dried and holds its form very well. It doesn’t warp like pressure treated wood which is why it is preferable for trellises, arbors and pergolas which all have mostly open designs. TIP – don’t use cedar for posts sunk in the ground unless you coat them to above the ground level (a roofing tar is the best choice for this), cedar rots quickly in contact with the ground. For posts you are better off using Pressure Treated wood and wrapping the posts with a set of cedar boards. That way you get the rot resistance below ground with the beauty of cedar above ground. Lifespan is generally between 8 and 15 years.
Other materials: there are many faux wood products available like “Trex” and “Azek” the main problem with using them for garden structures and trellises is that they are quite flexible and get even more so in the sun. They can be used as covering for a real wood structure, but are also quite expensive in comparison. Tropical hardwoods like Ipe and Teak are also used quite often for higher end and more permanent outdoor work. Lifespans for these materials are 25 years plus with proper maintenance.