Creeping Charlie's flowers emerge from the base of the leaves in clusters of two to six. As they mature, the flowers elongate and take on a trumpetlike shape with a slender base and a flared opening. They possess a large lower petal with two lobes as well as two smaller petals on each side and one top petal, which is identical to the bottom petal but smaller. Each flower is 1/2 to 3/4 inch long with a vivid, light-purple or violet coloration and a white throat. The throat also features speckles or stripes in dark purple or, sometimes, brown.
Creeping Charlie blooms from mid-spring until midsummer in most U.S. areas, although it also may sporadically produce flowers in autumn within warm climates. The greatest concentration of flowers appears in late spring and tapers as the weather warms. Deadheading will not prolong the blooming period or increase flower production, and so it is not necessary. Mowing the plant or severely pruning it before the flowers fade, however, controls seed production, which helps to control the plant's spread.
Color variations are rare among creeping Charlie plants, although cultivars and selected varieties may possess a markedly different coloration. "Dappled Light" creeping Charlie (Glechoma hederacea "Dappled Light") is one such cultivar. It is hardy in USDA zones 5 through 10 and grown for its variegated, golden and green foliage. Its flowers appear only sporadically in spring and early summer and are a pale sky-blue or medium blue rather than the brilliant violet found in standard creeping Charlie plants.
Despite the positive qualities of its blossoms and foliage, creeping Charlie often proves invasive in warm, humid climates. Much of the southern and eastern United States is overrun with creeping Charlie. So it is not recommended for planting in those areas. It can be grown safely, however, in containers in most areas or in flowerbeds that have a broad physical barrier such as concrete.