Picking the Right Paving Materials for Your Garden Project
Choosing the paving material could be the single most important decision when deciding on a paving project for your Garden. You may occasionally touch a plant, hold open a gate, or relax on a piece of garden furniture, but your feet are almost always in contact with your garden’s surface. Like plants, paving materials can add color, texture, and pattern to your garden. Unlike plants, which grow, bloom, and often go dormant as the seasons change, paved surfaces remain unchanged, and contribute in equal measure throughout the year.
The most widely available paving materials fall into two broad categories: quarried stone and composite material. Quarried stone, such as granite and slate, is dug and then shaped by splitting, cutting, or crushing. Composite materials like brick and precast concrete pavers are processed and molded when soft, then fired or allowed to dry.
The great range of paving materials makes shopping and designing fun, but the number of choices can also be a bit overwhelming. Each one has its advantages and disadvantages, and some are better suited than others to particular uses and locations. By understanding and exploring your options, you’ll be able to make the right choice for your setting and budget.
Note: Cost ranges given are averages for raw materials before installation from suppliers found throughout the United States. Expect some variability from region to region. The costs ranges are based on 2007 prices, but can still be used for relative comparisons of the various materials.
Stone is among the most nuanced and luxurious of paving materials. It’s also durable and versatile, offering an enormous range of colors, shapes, and sizes. From irregularly shaped flagstones for country-garden paths to precision-cut geometric blocks for a formal patio, there is a stone for every garden situation. All of this, however, comes at a price. Stone can be expensive to purchase and install. Paving-stone availability and prices vary from region to region, depending on the quantity purchased and your distance from the source.
There are a few points to keep in mind when purchasing stone for paving. A thickness of at least 2 inches is best for supporting frequent foot traffic and enduring the vagaries of settling or weather. Avoid rounded cobblestones, and flagstones with a polished or honed finish, which can be hard on the ankles and slick when wet. Instead, choose stones that are flat and have a natural-cleft surface and offer some grip or texture.
Before making a costly commitment to any material, check its color when wet. That pretty honey-tan granite you like so much could turn a lurid golden orange in the rain. Likewise, a subtle pattern in your sandstone may become objectionably bold when accentuated by moisture.
Sandstone is an excellent all-around choice
One of the most popular stones for garden paving is sandstone. It is tough enough for any paving application but is easier to cut and work than granite, which helps account for its lower cost. Sold under descriptive names like “Crab Orchard” (photo, below), “Colorado Red,” and “Pennsylvania Blue,” sandstone is available in many shapes and colors and is easy to come by in large quantities. Blue-gray and lilac-gray are common sandstone colors, but light gray, tan, soft golden cream, and orange-brown can be found as well. Expect some color variation in every lot of sandstone, along with occasional bands or blotches of contrasting color in each piece.
Gravel is a great option for a small budget
Gravel is easy to install and provides an attractive texture ideal for informal landscapes, short-term paving solutions, and gardens built on limited budgets. The objections usually raised against gravel is that it can become weedy and it’s too unstable underfoot. Weeds can become a problem if gravel is left untended, so it’s best to stay on top of them. To avoid issues with footing, select gravel that is labeled “1/4 inch minus”; anything larger is liable to shift noticeably. Avoid rounded, tumbled pea gravel as well. Sharp, angular, unsorted gravel will interlock as it settles to form a firm surface that will not spill, furrow, or shift. It also helps to tamp or compact the gravel, which should be done after a 2- to 3-inch-deep layer is put down.
Slate stands out for its texture and color
Often used as a flagstone, slate has a unique soft texture and subtle color palette that visually draws people in like a magnet. Its pastel blue-grays to muted reds and lavenders are beautiful, both to look at and to walk on. The same quality that makes slate easy to shape into relatively flat pieces can also limit this stone’s durability as an outdoor paving material. In areas that experience heavy rainfall or freeze/thaw cycles, slate will often flake and chip. The resulting uneven surface can puddle in wet weather, freeze over in winter, and trip up garden visitors in any season. Slate holds up best in relatively sheltered locations or regions with limited rainfall and mild climates.
Granite can’t be beat for strength and durability
For sheer durability, nothing can trump granite. It makes an elegant paving material for formal outdoor spaces and is often sold as cubes or brick-shaped pieces called sets (or setts) or as uniform-size (dimensional) flagstone. Besides its hardness and durability, granite offers what may be the widest color choice of all paving stones. From light through dark gray to grayish blue, tan, brown, honey yellow, green, orange, pink, and red—with or without conspicuous spots and blotches—the range seems almost infinite. The same hardness that makes granite so lasting also makes it relatively difficult to quarry and work, so it’s usually among the pricier paving stones. Because of the relatively high price, gardeners often use colorful granite sets as accents for more economical paving, as either inset patterns or decorative edges.
Limestone adds a distinctive look to paths and patios
Limestone is fine textured, so it takes on a distinctive, velvety finish when cut for paving. Its color range is a bit more limited than granite or sandstone. Dark gray, blue-gray, pale gray, cream, and tan are usually the easiest to find. Limestone tends to be more evenly colored than sandstone or granite, and its very fine grain makes it relatively easy to cut into all sorts of decorative shapes.
Limestone is uncommon in some parts of North America, including the Pacific Northwest and California coast, so you can expect its price to be close to that of sandstone or granite, depending on where you live. A word of caution about limestone: Its chemistry makes it susceptible to damage from acid rain, which can cause pitting and promote excessive wear over time. I wouldn’t worry too much, though, unless you live in an area with a serious acid-rain problem.