Calibrachoa — small, petunia-like ornamental plants (million bells)

Characteristics

Calibrachoa species bear many small blooms, usually with a five-lobed corolla and a tubular throat. Leaves are generally smaller and finer than those of larger related genera. Growth forms range from compact clumps to vigorous trailing stems. Flower colors span whites, pinks, purples, reds, yellows and many bi- or multi-colored varieties developed by breeders.

Cultivation and uses

These plants thrive in well-drained soil and prefer full sun to part shade. They are widely used in hanging baskets, containers and as edging or mass plantings where continuous bloom is desired. In temperate climates they are typically treated as annuals; in mild climates they may persist as short-lived perennials.

• Water: regular but moderate; avoid waterlogged roots.
• Light: full sun for best flowering, tolerate some afternoon shade.
• Feeding: benefit from regular, balanced fertilizer during the growing season.
• Maintenance: occasional pruning or pinching encourages branching and renewed blooms.

History and breeding

Originally native to parts of South America, these plants entered horticulture where breeders selected for smaller, longer-blooming and more compact forms. Modern varieties result from intensive breeding that emphasized color range, disease resistance and habit. Intergeneric hybrids with related genera have also been developed to combine traits.

Distinctions and notable facts

Calibrachoa is closely related to, and often compared with, the garden petunia. Differences include generally smaller flowers, a finer leaf texture and a trailing growth habit in many cultivars. Because of their prolific flowering and compact size, calibrachoas have become a staple for decorative containers and urban plantings. They share similar pest and disease challenges with other Solanaceae, such as occasional insect pests and fungal issues in poorly drained or overcrowded conditions.