Calibrachoa, also know as trailing petunia, or million bells, is a relatively new entry into gardens of the United States. Closely related to the petunia, which has been here since the early 19th century, Calibrachoa was released for commercial distribution in 1992. The plant is becoming more common, in large part due to the numerous blossoms it displays.
The foliage is medium green and consists of small, fuzzy oval leaves. The trailing stems of the plant feature many blooms that closely resemble petunias. They range in color from white, to cream, to bright yellows, oranges and pinks, reds, and lavender to deep purples. Some cultivars have a second whorl of petals within the flower.
Calibrachoa is fast- and low-growing and produces hundreds of flowers from early spring through fall. It grows well as a perennial in hardiness zones 9 through 11 and as an annual in more northerly climates. Calibrachoa is very heat tolerant. The form of the plant allows it to be used as a border or accent plant and it can also be kept in pots and hanging baskets. Propagation is by cuttings, as the plant produces few seeds.
Calibrachoa is a compact. rounded plant with stems that tends to trail. They grow from 5 to 10 inches in height and about 12 to 14 inches wide. They are prolific, producing many flowers. The blooms are about 1 inch in diameter and resemble petunia blossoms.
Calibrachoa should be planted in the early spring after the last frost. It prefers full sun but will tolerate light shade. Soil should be rich and well-draining and should be kept moist to prevent the plant from wilting. The plant does not require pruning. Iron may be amended to the soil to help prevent yellowing of new growth.
Ligher color varieties include the "Superbells Yellow," the light pink "Minifamous Double Blush" and the "Minibells Terracotta." Bright colored varieties include the "Cabaret Hot Pink," the "Minifamous Double Blue" and the "Minifamous Tangerine." Darker varieties include the "Minifamous Compact Dark Red" the "Cabaret Purple Glow" and the "Colorbust Chocolate."