Perennial flowering ground covers create a splash of color, filling spaces between shrubs and trees and transitioning between gardens and landscape features. The best ground covers are mounding or spreading plants and, when you throw flowers into the mix, the effects are stunning. You can find ground covers up to 3 feet tall for large areas of the garden to a few inches tall for small spaces and everything in between.
Creeping sedums (Sedum spp.), perennials, brighten up rock gardens, rock walls and small spaces in the garden. They typically grow 6 inches tall or less, forming a mat of fleshy foliage. Sedums grow in U.S. Department of Agriculture plant hardiness zones 4 through 9 with some variation depending on the species or cultivar.
Not all sedum put on a spectacular flower show, but the ones that do really stand out. A striking example is the cultivar 'Razzleberry' (Sedum 'Razzleberry'), that grows 6 to 8 inches tall in clumps up to 18 inches wide. Its deep pink flowers create a sea of color above blue-green leaves. Other sedums to try are Sedum album, a white-flowering type that grows 4 inches tall, or the 2-inch-tall ‘Rose Carpet’ (Sedum 'Rose Carpet') with rose-pink flowers. Not all sedums are short, and 'Autumn Joy' (Sedum 'Autumn Joy') proves this with its 1 to 3 foot-tall height. 'Autumn Joy' flowers in summer and fall and is hardy in USDA zones 3 through 11.
For small areas, try lesser periwinkle (Vinca minor), which grows 6 inches tall and is hardy in USDA zones 4 through 8. The lavender blue flowers bloom in late spring and early summer. The Madagascar periwinkle cultivar 'Carpet' (Catharanthus roseus '_Carpet'), which grows 3 to 4 inches tall with a 24 inch spread, produces vibrant colorful flowers all summer. This frost-tender ground cover grows all year in USDA zones 9b through 11. White herons bill (Erodium reichardii_ 'Album') creates a sea of white when its flowers bloom in the spring and summer. This low-growing 2 to 4-inch tall ground cover forms a dense mat of green foliage and is hardy in USDA zones 7 through 9.
Flowering ground covers that grow 1/2 to 1 1/2 feet tall are versatile and effective in a range of areas. Sea thrift (Armeria maritima), which grows 6 to 12 inches tall, has delicate pink flowers and mounding green foliage. This flowering ground cover grows in USDA zones 4 through 8. The turf lily cultivar 'Big Blue' (Liriope muscari 'Big Blue'), which grows in USDA zones 5 through 11, produces spikes of purple-blue flowers in the summer above mounding green foliage. This cultivar grows 12 to 15 inches tall in mounding clumps. The fragrant leaves and rich maroon flowers of the oregano cultivar ‘Herrenhausen’ (Origanum laevigatum ‘Herrenhausen’), hardy in USDA zones 5 through 8, works as a ground cover and an edging plant. It grows 12 to 18 inches tall and and 12 to 24 inches wide. Greater periwinkle (Vinca major) grows 12 to 18 inches tall, has sky blue flowers that bloom in the spring. It grows in USDA zones 7 through 9.
Taller Types for Large Areas
Ground covers that fall into the 2- to 3-foot-tall range add height to garden areas. The aromatic aster cultivar 'October Skies' (Symphyotrichum oblongifolium 'October Skies'), which grows 15 to 24 inches tall, is versatile for sunny areas. The sky blue flowers bloom in late summer and early fall inspiring butterflies to stop in the garden. 'October skies' is hardy in USDA zones 3 thorough 8. Walker's Low Catmint (Nepeta x faassenii 'Walker's Low') does just this with its mounding, spreading growth habit. 'Walker's Low' grows 24 to 30 inches tall with a 36 inch spread. The blue flowers bloom abundantly in summer attracting butterflies, bees and other pollinators. This flowering ground cover has fragrant foliage and is hardy in USDA zones 4 through 9.