Rock gardening, or the art of gardening where it looks like nothing can grow, is challenging in more ways than finding plants that grow well in rocky soil. If you love an artistic challenge, rock gardening can be quite satisfying.
The basic principles of garden design are color, texture, line and form. Before a plant variety is ever chosen, landscape designers envision the shape of the garden. This is equally important in rock gardening.
Your starting palette is dictated by the rocks themselves. If you are working with an existing area in your yard, your first colors are the rocks already in your new garden area. If you are building the rock garden from the ground up, you may be surprised to find rocks available in a fairly wide range of colors. Consider the naturally occurring rock in your area, as well as the colors in any existing landscape elements before you make a choice.
Your plant choices should provide colors that both complement the other plants used and provide an occasional contrast. The coloring of plants in all seasons should be considered, and should be chosen in a mix that will provide interest throughout the year. The focus should be on foliage as well as flowers. Plants in accenting colors can be used in the design to draw focus to a particular area, such as a water feature.
Attention to texture in your placement of plants – blending or mixing coarse and finely textured specimens – can make your rock gardening project look quite professional. If you’ve used a large variety of color, you may want less variety in your textures, and vice versa, in order to keep your garden from being too busy.
Line refers to the horizontal lines of the rock gardening area, or the shape of the garden on the ground, and the vertical lines, or height of the different plants and rocks. Horizontal lines should work with the overall shape of your landscape. For example, is your driveway curvy or straight? How about walkways and patios? Even if you are rock gardening in an existing rocky area, you can determine the horizontal lines by movement of any loose rocks, placing a few additional rocks, and the placement of your outer plantings.
Your garden should generally include plants and elements of varying heights to avoid appearing flat. Vertical lines include all upright elements in the area, like fence posts and telephone poles, not just trees. Consider the impact of all these items on your vertical lines when choosing plants.
Form refers to the shape and character of your plants. Are they tight and compact, spreading, arching or creeping? Remember, the form they show you in the nursery as a young plant may not match their mature shape, so be sure to do your research. Some plants can be pruned to showcase their form, others will be themselves no matter what. Including consideration of form in your planning will ensure that your garden does not smother itself or hide the very rock features you are trying to show off.