Arbor vs. Pergola Explained: Uses, Plants, and History

The words pergola and arbor are often used interchangeably to describe two similar outdoor structures. Both are built with posts that support an open roof of beams or lattice. And both often support vines or climbing plants. Basically, an arbor looks like a smaller version of a pergola.

Arbor and pergola should not be confused with a gazebo, which is always a freestanding open garden structure, typically with a hexagonal or octagonal shape (modern ones may be square or rectangular) and a roof. The difference between a freestanding arbor and a gazebo is basically the size. The point of an arbor is to act as a garden or landscaping accent, but a gazebo is a larger space fit for dining or other leisure activities. Unlike an accessory dwelling unit, neither of these structures is inhabited.

What used to be simply called a patio roof during the post-World War II housing boom—when outdoor projects proliferated and Lane Publishing (Sunset Books) stepped up its production of how-to guides for everything—is now referred to as a pergola, and sometimes, an arbor. 

Difference Between Pergola and Arbor at a Glance

Arbor vs. Pergola Design and Uses

Arbor

You can place an arbor anywhere in your backyard. But this freestanding structure typically serves as an entrance to a part of a yard or garden. An arbor also serves as a small shelter for a bench or seating area, often tucked into a garden or off a path with plants climbing or vining up and overhead. Arbors include two or four posts with a simple slatted roof (often arched, but not always). The sides of an arbor are be open or covered with lattice or trellis work for a more enclosed effect and to help vines better attach.

Arbors are available ready-to-use or as kits. You can make it a do-it-yourself project or have one custom-built by a carpenter or contractor. It is made of wood, metal, or vinyl. An arbor is smaller, so it may be less expensive to build and install than a pergola since it requires fewer materials and less labor.

Pergola

Often built over a patio or deck as a shade structure, a pergola is based on a similar post-and-beam construction as an arbor. When attached to a house, a pergola will extend from the exterior side or roof, creating a shaded or semi-shaded space that links the interior of the house to the landscape. In other words, it provides some sort of roof for a patio, deck, or outdoor room.

A pergola can be connected to a house on at least one side, consist of a series of independent columns supporting beams that form an open roof, or be a freestanding structure. 

As a freestanding structure, a pergola is identified by having four or more posts or columns. It supports a roof that is traditionally flat, with beams left alone in one direction or topped with cross beams or slats. The pergola's roof is either left open, covered with weatherproof fabric or another lightweight material, or it supports fast-growing vines. If the vines or cloth cover one side of the pergola and patio area, it serves as a privacy screen and also blocks an unsightly view of your neighbor's yard.

A pergola is usually built from a kit, is a do-it-yourself project made from plans, or is custom-built and designed by a contractor. Size, budget, time, the scope of the project, and your DIY skills and level of enthusiasm will determine who builds it and how it gets built. It may cost more to build a pergola than it does an arbor, largely due to its size and materials.

If you need inspiration, take a look at these stunning pergola designs.

A Brief History

Originally created to support a climbing plant or vine, a pergola is one of the earliest types of garden structures. Pergolas were used in ancient Egypt, Greece, and Rome. In the late 1800s, pergolas were popular in England to support and show off beautiful flowering vines including roses, honeysuckle, wisteria, and clematis.

Pergola comes from the Italian word pergula, which means projection. This refers to the wood structure in Roman gardens that projected from exterior walls and was supported on one side by columns or pillars. Architects of the Italian Renaissance built pergolas in an attempt to reproduce the villas of Imperial Rome. In its earlier forms in 19th-century gardening books, pergolas were described as "covered (in vines) walks."

Arbors date back to early Egyptian and Roman gardens and were used throughout Europe by the late 16th century. The term arbor, or arbour, is an English word, believed to be derived from the Old French herbere or Anglo-French herbe, meaning herb or grass.