Rock Garden Ideas for Small Spaces

Instructions

1. Build the First Course

   Clear the area of grass or other organic material, if necessary. Be sure to dig up sod and other plants below the roots to prevent new shoots from coming up later in your rock garden. Lay out a circle of rocks as the perimeter of your base, making the diameter about 4 feet (or as desired). This forms the foundation of your garden and creates some elevation above the surrounding ground. You can use up most of your largest, least attractive rocks in this bottom layer, but it does not require stones larger than about 12 inches in any dimension.

   Fill the area inside the first course with sandy soil, which provides good drainage. If all you have is a clayey soil, add sand and compost to it to promote better drainage. Walk on the soil to pack it down.

2. Add the Second Course

   Plan the second course of stones. This can simply be a smaller version of the first course, forming a circle within a circle, or it can take the form of one or more bands of stone that pass through the center of the bed perimeter. In any case, the second course should provide plenty of room for planting between the bed perimeter and the second-course stones as well as in any additional spaces created by the second course.

   Place the second course of stones according to your plan (and don’t be afraid to experiment). Since you used your heaviest stones for the first course, you have lighter, more easily maneuvered stones to use for the second course. Try to use the best-looking stones here (any size is fine) because they will be more visible than the foundation rocks.

3. Select Plants for Your Rock Garden

   Start your plant selection by choosing a color scheme that will work well with your stone. For example, if the garden is made primarily with red sandstone, you’ll want some plants with a hint of red in them, as well as some plants displaying silver, yellow, white, or other complementary colors.

   In addition to selecting for color, choose plants that thrive in well-drained soil. Also, confirm that the plants have similar watering requirements and are suitable for the amount of sunlight the garden receives. Drought-resistant plants are best, although you can make an exception for a particularly handsome specimen that you can treat as an annual (that is, temporary) plant. Finally, seek variation in plant height and leaf texture for maximum visual impact and interest.

4. Plant Your Rock Garden

   Arrange the plants in your rock garden while they are still in their pots. Usually, it’s best to plant in threes: grouping three of the same kind of plant together or in a strategic arrangement. Keep in mind that you will intersperse rocks among the plants.

   Once you’ve settled on a layout, begin planting with additional soil as needed, adding rocks for decorative effect as you go (if you add all the rocks before planting, they’ll just be in the way of your digging.) 

   If you want to cover small areas of soil with rock mulch (to prevent weed growth), use small stones of the same type (or at least similar coloring) as the major stones forming the rock structure.

Sample Rock Garden Design

Here is a good sample selection of plants for a small rock garden, chosen for color, care requirements, size/height, and texture:

• 6 pots of Scotch moss (Sagina subulata Aurea) for short plants with a touch of yellow
• 1 yellow daffodil (Narcissus) for more yellow; miniature varieties are best for small rock gardens
• 3 pots of wood spurge (Euphorbia amygdaloides Purpurea) for their yellow blooms and red stems; taller plants that give the composition some depth
• 3 pots of hens and chicks (Sempervivum tectorum) for more red color, along with some low-growing foliage
• 3 pots of snow-in-summer (Cerastium tomentosum) for silver foliage and white blooms
• 1 lamb’s ear plant (Stachys byzantina) for more silver foliage
• 3 pots of candytuft (Iberis sempervirens Purity) for their striking white flowers

This rock garden will look nicer in spring and early summer (when the plants are in bloom) than it will in late summer. That’s an example of a compromise you must make unless you have a space large enough to implement a sequence-of-bloom agenda. For colorful blooms throughout the summer, you can easily add the annual, portulaca, to the mix.

Another compromise is made with Scotch moss, which is not drought-tolerant. This is a case of sacrificing longevity for a temporary pop of color and texture. Scotch moss is suited to planting zones 4 to 9 and bears small white flowers, but it is grown mainly for the solid carpet of yellowish-green that it provides. It grows in full sun to part shade.

The only plant in this sample design that is grown more for its flower than its foliage is the daffodil. The relatively coarse textures of the lamb’s ear, wood spurge, and hens and chicks contrast well with the other plants, all of which have more delicate foliage. As the years go by and the daffodil and lamb’s ear spread, you can divide them. If you decide that they clutter up your rock garden too much, transplant them to somewhere else in the yard.