Calibrachoa (Calibrachoa x hybrida or Calibrachoa clade) was split off from the petunia family (Petunia clade) in 1989, but the two plants have similar water, container floor, and temperature requirements. Calibrachoa, also known as coastal petunia, trailing petunia or million bells, is a slightly smaller plant with smaller flowers than a petunia. Calibrachoa grows in mounds 3 to 9 inches tall or as trailing stems about 20 inches long, while petunias grow 10 to 14 inches tall and 2 to 3 feet wide. Calibrachoa grows as an annual in U.S. Department of Agriculture plant hardiness zones 9 through 11 and elsewhere, according to the Missouri Botanical Garden.
light and waterCalibrachoa thrives in full sun with six to eight hours of direct sunlight per day and also tolerates partial shade, says the Missouri Botanical Garden, where it blooms a little less profusely. The plant needs regular watering every week during the growing season, and more if you’re growing it in a container. Allow the soil to dry out completely between waterings. Calibrachoa is drought tolerant but thrives best with adequate water.
soil and foodPlant Calibrachoa in soil that’s well-draining and rich in organic matter for the best results, advises Floridata. Calibrachoa prefers soil with a neutral pH, neither too acidic nor too alkaline. It will be best if fertilized every few weeks during the growing season; Use an all-purpose fertilizer applied according to package directions.
Pruning and pinchingUnlike petunias, Calibrachoa doesn’t benefit from pinching off wilted blooms; As a hybrid, Calibrachoa doesn’t produce seeds from spent flowers, so removing those flowers won’t encourage the plant to produce more. The flowers just fall off by themselves. But you can prune trailing stems to encourage bushier, more compact plant growth, says PW Proven Winners.