Creating rock and flower gardens is ideal for sloping landscapes or terraces. Rocks add visual interest as well as control soil erosion, while plants add color and texture, and act as a ground cover. According to the Colorado State Extension Service, these gardens work best with one geological rock type intermingled with plants and flowers that thrive in well-drained soil.
Use more than one size rock throughout the space to add visual interest. Choose plants in rock gardens, starting with the ones below, to reduce maintenance. These plants grow to approximately the same size and will tolerate similar conditions. In addition, each of these plants will fill in small crevices as well as steep slopes.
Hens and Chicks
"Hens and Chicks" (Echeveria elegans) is one of the most popular plants used in rock gardens. Hens and Chicks, a succulent species, requires little water and can be planted between rocks in very little soil. They are compact plants that have blue-green foliage and will tolerate partial shade.
Stonecrop (sedum) is a mat-forming succulent that works well in between rock formations or along crevices and rocky slopes. Stonecrop produces small star-shaped yellow flowers when planted in the sun. Sedum prefers well-drained soil and will fill in almost any outcropping. For this reason sedum can be planted in rock gardens as well as being used as a slope groundcover.
Bees Ruby (Armenia psuedoarmenia) consists of evergreen tufts of linear leaves with bright pink flowers. Bees ruby is used to add visual interest to most rock gardens. This perennial plant has turf-like foliage and small flowers that develop thin stems that stand out against the foliage. According to Wild Ginger Farms, an online resource and retailer, Bees Ruby is an excellent rock garden flower because of its grass-like qualities that fill in bare spots along hard-to-reach-slopes as well as the fact that this plant is winter-hardy.
Rock cress is another low-growing creeping plant used to fill in spaces between rocks in a rock garden. Rock cress, Aubrieta Deltoidea, produces a cluster of highly fragrant pink, white or lavender flowers that stay close to the ground similar to phlox. According to The Gardeners Network, a gardening Web site, rock cress is easy to grow and works well in places where it is hard to cultivate grass or other foliage. These perennials enjoy full sun but will tolerate partial shade as well as slightly dry conditions. In addition, rock cress is a hardy plant that will survive frost.