A Garden That Rocks

Pretty in its own right, a rock garden can camouflage site faults and cut down on yard work.

STEP 1

With a garden spade, mark the boundaries of what will be your rock garden. Clear this site of grass, roots, and any unwanted elements and debris. To inhibit the growth of weeds before the plants fill the space, place a layer of biodegradable weed barrier or multiple layers of newspaper over the dug-out area. A rock garden should be slightly sloped when it’s laid; you can use small rocks under the topsoil to create terracing. If your garden isn’t naturally rocky, consider what type of stones you want to import. See “Rock Options” (opposite page) for ideas.

STEP 2

Sometimes it’s helpful to sketch the rocks’ placement first, and then move the rocks. They should have a random arrangement to give the garden a natural look. Try rocks grouped in twos and threes.

Also plan for a transitional area between the rock garden and the lawn, walk, or driveway. By using gravel, you can plant a low-maintenance scree garden in this space. (A scree bed mimics natural scree—ground where rocks near the surface have shattered to become a stony debris field. A welldrained, sunny scree garden can host Mediterranean plants, small succulents, etc. Let the scree follow natural contours; it shouldn’t be too level. Use at least a 3" depth of pea gravel.)

After planning, start placing the stones. Position boulders or large rocks first because they are the focal points. They may need to be supported with bricks or smaller stones underneath. Use safe lifting practices and know your limits—this is laborious work. Use a hand truck or a dolly to roll stones into place, and a shovel or a crowbar to adjust their position. Have an assistant help.

Next come the medium-sized rocks. Play with sizes and shapes; for example, you might pair a large boulder with a smaller one or a smooth rock with a sharper one. Partially submerge some or most of the stones for a natural look. At this point, spread topsoil (before adding the smallest rocks). The topsoil laid over the weed-resistant layer should have good drainage: Mix two parts fresh, weed-free topsoil with one part of a material such as gravel, lava rock, or sand. Tamp down the soil and water with a garden hose. Let it settle for two days before planting.

STEP 3

Now you’ll place plants next to rocks or in crevices between rocks. Choose plants for sun, part shade, or shade, depending on the specific conditions of your garden. As you place the plants, cover any bare areas with smaller stones. Because the site is sloped, start at the bottom of the site and work upwards.

Limit the number of different types of plants you use, which is more natural and pleasing to the eye. Don’t cover the garden completely with plants—the rocks should be visible. Leave enough space between plants so that they can spread out as they grow. Consider the ultimate height of plants for both their placement and the scale of the garden. You may not want plants that protrude too high above the rocks, or you may want a mix of low and taller.

Consider color, too. Granite grey looks good with colors from cool blues to warm pinks and bright white. Sandstone, however, may look better with plants limited to a warm palette. Finally, fill your scree bed with gravel, pea gravel, or a combination of smallscale materials. It’s optional, but if you have full sun, you may also want to plant alpines and groundcovers in the scree.