Calibrachoa Hybrids

Just as one can’t judge a book by its cover, a gardener can’t judge a plant by its name. In fact, for over a century and a half Calibrochoa were misnamed petunias. Early species introduced to America’s shoreline were called beach or seashore petunias and are found along the coast of California and from Maine to Florida. The South American native and chromosome cousin of petunias was positively identified through DNA as genus Calibrochoa in 1990. Its identity crisis hasn’t changed this plant’s performance.

In 1988 a Japanese company, Suntory Ltd., collected wild species for an extensive breeding program. Their research led to the introduction of Calibrachoa hybrid ‘Million Bells’ into the marketplace in 1997.

Hardiness

The colorful floriferous bloomer trumpets its way into the garden for a three season stand. Calibrachoa grow in hardiness zones 3-11 from early spring until late fall. In zones 9-11 they act as perennials.

Multipurpose Annual

Gardeners find the low-growing trailing plant with small trumpet flowers plays multiple roles. The mounding and cascading habit makes it ideal for hanging baskets. It is equally at home in patio planters or windowboxes. When perennial beds need front color, it fits right in. Calibrachoa adapts to rock gardens just like portulaca. The plant with a height of only 6-10 inches has a spread of 24 to 36 inches making a fabulously flamboyant ground cover. New color additions debut each year and include shades of magenta, purple, pink, rose, crimson, yellow, terra cotta, tangerine and white.

The petite one-inch wide trumpets self-clean so dead-heading is not necessary. The more sun received by the plant, the heavier the bloom. Heat and drought do not reduce blossoms but shade will. If plants seem to be declining in extended heat, prune back by half and watch them spring back. Container plants need more frequent watering.

Calibrachoa are heavy feeders. Feed container plants twice a month and bedding plants monthly using a liquid fertilizer. If planted in the ground, Calibrachoa prefer a well-drained slightly acid soil. A pH near or below 6.0 is best.

The rich nectar in the tubular trumpets attracts butterflies, bees and hummingbirds.

Minimal Problems

Pest and disease problems are minimal. Aphids, leaf miners, thrips and white flies can be problems. Control with insecticidal soap. Root rot occurs from overwatering and poor drainage in containers.

Propagation

Calibrachoa available to the public are patented plants. It is illegal to propagate them. However, calibrachoa can be propagated by stem cuttings. The garden hybrid produces few if any viable seed. Seed is not available commercially yet. Since at least eight companies are breeding new cultivars of Calibrachao, the horizon looks hopeful for seed, a perennial series, and new color variations.

Evaluation

At the University of Georgia Trial Gardens Calibrachoa hybrids are evaluated for number of flowers, leaf color, uniformity of growth habit, resistance to diseases and pests, and overall appearance from spring to November. The following cultivars scored ‚”best of the best” in 2008:

• ‘Million Bells Plum’
• ‘Aloha Blue Sky’
• ‘Aloha Tiki Strawberry’
• ‘Noa Ultimate Pink’
• ‘Million Bells Trailing Yellow’
• ‘Million Bells Chiffon’

Trial this carefree, dependable, nonstop bloomer in your garden this year.