Beauty of Planting Rocks

Japanese masters have perfected the art of placing rocks in gardens for the most natural effect. The goal is to make rocky outcroppings modeled after those of the mountains of Japan. There will be no hint that anything was man-made. (Photo courtesy of Maureen Gilmer, Do It Yourself Network.)

Japanese masters have perfected the art of placing rocks in their gardens for the most natural effect. Their goal is to make rocky outcroppings modeled after those of the mountains of Japan. There will be no hint that anything was man-made.

Boulders added to your garden can suggest wild places within the confines of a suburban back yard. But such a rock must never look as though it were a meteor that has just plummeted into your shrubbery.

You may be surprised that no two natural stones are exactly alike. Each exhibits a difference in color no matter how slight. Mosses and lichens may change the face of a stone, as will iron stain and weathering. Stone shape is equally variable, with some rounded by water to be smooth as glass, and others chipped into sharp edges by landslides or expanding ice. The type of density may be solid granite or the rough honeycomb volcanic rock.

It is essential that landscape boulders be carefully chosen so that they are well-matched. This guarantees the whole composition will be visually connected. Each boulder will have a top and bottom. If you study boulders in the rock yard, there will be a clear difference in color where the pale bottom of the rock originally sat in the ground. The upper side will be weathered, and if you're lucky it will show colored lichens or mosses too. When choosing boulders, those with such coloration are always preferred.

Once in your garden you should "plant" each boulder with the weathered side up. Planting ensures that the boulder stays in place through freeze or thaw, and if on a slope you need not worry about it rolling downhill. In Japanese gardens there are often tall "standing stones" that may require more thorough planting if you want them to stand upright without gradually listing when the ground is saturated.

To plant your boulder, first dig a shallow bowl, then set the boulder within. Study it awhile from all angles to decide which side of the rock has the most attractive face. This becomes the "front" of the stone. Pivot that stone until the front faces in the direction you see most often, which is the garden version of "putting your best foot forward."

Once you have the boulder placed properly, fill in around the edges. This makes the rock appear more like a natural outcropping. It's rare in nature to see a single stone sitting by itself, so to make it look less meteorlike, include at least two other well matched smaller stones of different sizes.

The final step in making that boulder look natural is to plant around its edges. Plants tend to grow there in the wild because moisture is trapped in the soil under the rock. Use a small tree to call attention to the rocks, and plant clumps of iris or ornamental grasses beside them for drama. Then surround it with dense, matlike groundcover to nestle the stone.

It is always best to use the rock indigenous to your area, which is plentiful and less expensive. Be aware that a large boulder is incredibly heavy for its size, so it's wise to hire someone well insured to deliver and set it for you. Once roughly placed, you can then take your time to study the unique character of each stone. When completed, this project will grant you a newfound skill of the Japanese garden masters.

(Maureen Gilmer is a horticulturist, landscape design consultant, and author of 14 books. Distributed by Scripps Howard News Service, www.shns.com.)