Every garden -- whether rock or otherwise -- needs a border to separate it from the rest of the yard and to define the space within it. Rocks are a natural choice for a border material, but when the garden itself is composed mostly of rocks, placing them on the border may seem redundant to you. If so, never fear -- you can turn a number of other materials into an attractive, easy-to-make border.
Wood Borders Rock
A wood border nicely finishes any combination of rocks and succulents. By balancing the elements, you're creating visual harmony, and construction won't be a time-consuming task. If you need to curve the border around an irregularly shaped garden bed, consider pounding lengths of two-by-six lumber vertically into the ground or installing half-log edging, which you may be able to find at your local garden center. You can also use old logs or even scrap wood.
Rocks and Plants
Edging your rock garden with plants is the reverse of edging your flower garden with rocks. Choose a perennial ground cover, such as bishop's hat (Epimedium grandiflorum 'Lilafee'), a shade-loving perennial hardy in USDA zones 5 through 8. For sunny locations, consider sea thrift (Armeria maritima) or three-leaved stonecrop (Sedum ternatum). Both are hardy in zones 4 through 8 and are drought-tolerant.
Bricks, Pavers and Cinder Blocks, Oh My!
Take advantage of the durability of masonry by creating a border using new or reclaimed bricks, pavers or cinder blocks. Once you tap these onto a bed of sand, they're virtually maintenance-free. This type of border is inexpensive -- if somewhat labor-intensive -- and may require occasional weeding. Reduce the chances of weed growth by placing the bricks close together, mortaring them or filling in the gaps between them with sand.
Pipes for the Masses
A trip to your local recycling yard will probably reveal a trove of old steel pipes. Cut them into 2-foot lengths and pound them into the ground to border your rock garden. Place pipes of various diameters in the ground at random depths or use pipes of the same diameter and place them at the same depth. Either way, you can fill the pipes with dirt to stabilize the structure and even plant a few flowers in them for good measure.
Nothing says "Zen" like a rock garden, and if yours is a creation of abstract beauty intended to inspire a meditative appreciation of nature, add even more Asian inspiration with a bamboo border. Weave strands or thin shoots through stakes placed 4 to 6 inches apart to create a small fence-like structure. Filling in your rock garden with small-diameter gravel and adding a small bamboo fountain complete the Zen motif.
Fruit of the Vine
If you enjoy a glass of wine with your meals, here's a good way to make use of the bottles. Strip off the labels, dig holes around the garden and drop them spout-first into the ground. Place them next to each other or incorporate them as features into a border made with another material, such as bamboo, pipes or even large clam shells. It won't be long before the glass will begin to weather and develop an attractive patina.