Perennial plants are those that live for three years or more, often "dying" in the winter only to pop up again the spring. While flowering perennials are lovely in any garden, some gardens aren't well suited for tall growing perennials such as Foxgloves (Digitalis) and Hollyhocks (Alcea rosea), which can reach heights of five feet, dominating the landscape. A number of low-growing perennial flowers of 18 inches or less can offer bursts of color close to the ground.
A native of Western Asia and Southern Europe, Primrose (Primula vulgaris) is a spring-blooming perennial that grows close to the ground, reaching a height of about 6 inches. The plant has semi-evergreen leaves topped with tubular flowers in colors ranging from purple and pink to red and yellow, depending on cultivar. The plant thrives in moist, humus rich soil, but it will flounder in soggy or swamped soil. Primrose should be planted in filtered sunlight for best results in USDA zones 4 to 8.
Reaching an average height of between 8 inches and 10 inches, Mountain Sandwort (Arenaria montana) is a diminutive summer-blooming plant that boasts floppy, creamy white flowers atop dark foliage. Shrub-like and bushy, the perennial plant thrives in rocky, sandy soils and can be grown in a rock garden. The plant should be watered about once a week to keep the soil moist. Mountain Sandwort will grow in full sunlight or partial shade in USDA zones 4 to 7.
Lily of the Valley
Blooming in mid or late spring, Lily of the Valley (Convallaria majalis) is a perennial herb that produces columns of fragile, white bell-shaped blooms amid waxy green foliage. The small plant usually does not reach heights of more than 8 inches. Lily of the Valley is adaptable to different soil types, growing in well-drained, sandy soils as well as heavier clay soils. The soil should be kept moist, but not water logged--water once a week or so. Lily of the Valley is sensitive to sunlight and should be grown in partial shade or full shade in USDA zones 2 to 7.
Rarely reaching heights above one foot, Chinese Astilbe (Astilbe chinensis 'Pumila') is a bushy perennial that produces deep rose pink flowers throughout the summer and well into fall. Often grown for its dense, deep-green foliage, Chinese Astilbe is well utilized as a ground cover plant or as a container plant. The perennial will thrive in neutral, well-drained soil in either full sun or partial shade. The plant should be watered every week or so during hot summer months. Chinese Astilbe is best suited to USDA zones 5 to 9.