Callie, petunia’s upstart cousin, bursts with floral fireworks
By University of Missouri Extension
COLUMBIA, Mo. – Most flowering annuals in gardens around the U.S. have stood the test of time, said University of Missouri Extension horticulturist David Trinklein. For example, geraniums were planted in Europe in the 17th century and have been an American favorite for more than 200 years. Petunia, as we know it today, appeared in gardens in the 1800s.
While new flowering species are introduced on a regular basis, few have replaced longtime favorites, said Trinklein. An exception is calibrachoa, a relative of petunia that debuted in the 1990s and has taken the gardening public by storm.
Calibrachoa, like Petunia, is a genus in the nightshade plant family (Solanaceae) and is native to South America. It took an unusual journey from Brazil to Japan and Europe and, finally, to the United States to become one of the hottest sellers in the bedding plant industry today. Along the way, breeders transformed it to a flowering annual worthy of gardeners’ attention.
With flowers about an inch in diameter, callies look like miniature petunias. What sets them apart is the wide array of colors and patterns of their flowers. Varieties with yellow, orange or bronze flowers are commonplace among calibrachoa.
Since callies produce very few seeds, their energy is devoted to producing more flowers. While this enhances their attractiveness, it means most varieties need to be vegetatively reproduced, which costs more than starting plants from seeds. “Expect to pay just a bit more for calibrachoa plants than you would for most seed-propagated petunias,” Trinklein said.
The added expense is well worth the investment, he said. Calibrachoa plants are heat-tolerant and produce loads of flowers. They are semi-trailing and grow to a height of about 12 inches.
They are excellent plants for a combination planter or hanging basket, Trinklein said. “As a matter of fact, calibrachoa probably performs better in a container filled with a soilless growing medium than in a garden bed or border.” This is especially true if the soil lacks good drainage.
However they are used, callies need full sun. Partial shading leads to decreased flowering and a less attractive display of color. They are fairly heavy feeders, so give them additional fertilizer during the growing season. Feed every other week with a liquid or soluble fertilizer according to label directions, said Trinklein.
Calibrachoa seems to need more iron than most bedding plants, so maintain the growing media at a pH in the 6.0 range, which is slightly acidic. Feed with iron sulfate or chelated iron if new growth is yellowish.
Callies are relatively pest-free but can suffer from root rots such as pythium and phytophthora if overwatered or grown in poorly drained soil.
Nearly every major seed or plant company has jumped on the calibrachoa bandwagon with their own series of this new bedding annual. Series to look for in the spring include Million Bells, Super Bells, Cabaret, Cruze, Calipetite and Can-Can. All bring dazzling color and outstanding performance to the garden, said Trinklein.
“This year, add some floral fireworks to your containers and hanging baskets by including calibrachoa,” he said. “It just might become your new favorite bedding plant.”
