Tips on Garden Border Materials

Edging materials improve the look of your garden beds, while keeping mulch and soil in and grass and gravel out. But what kind of edging is best?

One of the most commonly used materials is treated landscape timbers. They’re inexpensive, last a long time and are easy to install. They may be stacked end to end or stacked and secured with long galvanized nails.

Railroad ties are inexpensive, last forever and make a bold statement, but they’re very heavy and difficult to handle. It’s best to stick with old ties: they’re cheaper and look nicer, and the creosote from new ties may leach out and contaminate plants and soil.

Also good to use for borders are conventional 2″ by 4″ pieces of lumber: redwood, cypress and cedar are good choices, but the longest-lasting, most rot-resistant wood is pressure-treated pine that’s rated for ground contact. The chemicals used to preserve the wood are safe for soil and plants, but it is recommended to wear a dust mask when cutting pressure-treated wood and gloves when handling it. These woods do a fine job at straight-line borders, but can’t handle curves.

Make wooden edging by buying 8′ lengths of treated or rot-resistant wood and cutting it into random lengths, then placing the pieces in a shallow trench along the edge of the garden. Fill in the trench, and tamp the soil gently to settle the border in place.

Bender board may be hard to find. It comes in long rolls and conforms to even the tightest curves and turns.

Plastic has been the edging material of choice for years. It’s easy to install, as long as the day is warm and the plastic is pliable.

Metal edging is preferred by professional landscapers. It’s pliable, may be painted and lasts forever, but it’s expensive. If the soil is soft, install metal edging by laying it along the border of the garden bed and tapping it in place with a hammer, using a piece of board to cushion the blow. If the soil is hard, dig a shallow trench first, then lay the edging in the trench and fill with soil.

Borders of stone, concrete or brick are the most expensive, but also the longest-lasting choice. Unless the stones are fitted together with mortar, however, weeds and turf grasses will quickly grow between the cracks.

Cement or brick pavers are reasonably inexpensive. Bricks tend to be more attractive and versatile since you can use them on their side, set them end to end or lay them on a diagonal pattern.

Many types of precast border stones are also available at garden-supply stores. Interlocking pavers are perfect for do-it-yourselfers. They’re expensive, but may be used in a variety of ways, including side by side to create borders or stacked to build raised beds.

If the purpose of the border is to prevent grasses or invasive plants from entering your flower beds, the edging must extend at least 2″ below the soil surface.