Rock gardens need plants with shallow roots and a tolerance for dry conditions. This is especially true when the garden is located on a sunny slope. Prevent erosion and provide a burst of color with the following easy to grow plants. You can use a variety of different plants, or simplify and specialize in one type of plant. Start with basic perennial plants that spread to fill any bare spots.
Creeping phlox, also known as phlox subulata, produces fragrant, star shaped blue, red, white or pink flowers. The mat-like foliage holds well between rocks. The dense root system in this ground-cover can also help prevent erosion, making it a good landscaping solution for slopes.
Rock cress, or Aubrieta, forms a dense show of deep purple or blue-purple blossoms. A hardy evergreen, this plant will grow and thrive between rocks and crevices in the full sun. In order to keep the bushy plant compact and low to the ground, it is best to cut it back after it blooms, advises GreenZoneLife website. This yearly maintenance will force it to fill in the spaces between rocks and create a mat-like carpet of flowers.
The evergreen shrub, candytuft, grows up to 10 inches tall and will spread up to 20-30 inches wide. The smooth leaves grow approximately 11/2 inch long. White and pink flowers bloom in the spring. These plants will tumble down rocks on a sunny slope. Iberis sempervirens is the variety commonly found for sale in garden centers.
Hens and Chicks
Hens-and-chicks produce hairy, grey-green rosettes that will grow and spread between rocks and cracks in the full sun. Sempervivum tectorum is the Latin name for this evergreen succulent. Known for the large rosettes referred to as the “hens” and the smaller rosettes that are called the chicks. The plant also produces a flower stalk when it matures, then the plant dies, according to Wiseacre Gardens. This resilient plant basically takes care of itself. You can propagate the plant by breaking off a rosette and planting in a new area. The rosette only needs contact with the soil in order to root.
Trumpet gentian, Gentiana clussii, blooms in both spring and fall. It is well-acclimated to rocky soil and harsh dry climates. This low-lying ground cover produces several short vines with dark, navy-blue flowers. Ideal for rock gardens on a sunny slope, the trumpet gentian has shallow roots and will spread between and over rocks.