Calibrachoa

( kal - ih - bruh - KOE - uh )

At-A-Glance Information

These flowering perennials are often sold as annuals and need full sun to light shade conditions and moderate water. They are commonly called Trailing Petunia or Million Bells. The flowers are similar to those of Petunia plants, and species are native to Brazil, Chile and Peru. They are typically found growing in grassland or scrub landscapes. Most of the garden ornamentals are hybrids; blooms can be single or double, and fall off the plant as they fade, but will keep forming all season long. Flowers can be white, yellow, orange, apricot, red, pink, blue, burgundy, lavender and purple. These come in both upright and trailing habits, great for a variety of planting situations including containers and hanging baskets. Plant Calibrachoa in mixed beds and borders, on patios or walkways, or simply to add color to mixed beds and borders.

Calibrachoa Species and Varietals

The genus Calibrachoa is a member of the Nightshade plant family Solanaceae, and includes 28 distinct species. The genus was named by botanist Vincente Cervantes for botanist and pharmacologist Antonio de la Cal y Bracho. The best growing zones for Calibrachoa are USDA hardiness zones 9-11 or Sunset growing zones 8, 9, and 14-24. To find your zone, click here: Zone Map.

Calibrachoa elegans (Million Bells, Mini Petunia)
This annual species is native to Brazil, and forms a small subshrub that produces profuse shows of flowers in spring and summertime. Individual plants reach up to between 6 and 12 inches tall, and have a trailing habit, making them suitable for hanging baskets.

Calibrachoa x hybrida (Hybrid Calibrachoa)
This group of Calibrachoa plants have been bred for their various flower colors and compositions, compact or trailing habits, or resistances to diseases such as Powdery Mildew.

'Cabaret Goodnight Kiss'
Deep magenta petals with black and yellow centers.

'Callie Dark Red'
With deep red flowers that have dark veining.

'Callie Purple'
A variety with dark purple blooms.

'Callie Yellow'
With simple yellow flowers.

'Callie Summer'
This hybrid produces pink-salmon blooms with darker centers and yellowish throats.

'Cappuccino'
With light pink to white flowers that have magenta veining and yellow throats.

'Chameleon Indian Summer'
These plants produce rich orange-red to pink flowers with dark centers and yellow mottling.

'Eyeconic Purple'
Light periwinkle petals with dark purple centers and small yellow eyes.

'Eyeconic Strawberry'
With fuschia blooms that have yellow centers.

'Kabloom White'
A classic white Calibrachoa hybrid.

'Minifamous Uno Double Dark Blue'
With dark purple double flowers.

'Superbells Double Vintage Coral'
These plants produce yellow and pink ruffled blooms.

'Superbells Lemon Slice'
With striped yellow and white flowers.

'Superbells Tequila Sunrise'
Blooms have tones of orange, red, coral, and gold.

'Superbells Watermelon Punch'
Bright watermelon-red blooms with dark centers.

'Sweet Chimes Red Wine'
With cherry-red flowers that have yellow centers.

Calibrachoa parviflora (Seaside Petunia)
This species is native to coastal regions in South America, Mexico, Australia and the southwestern United States. This plant produces slender, branching stems that creep along the ground and form roots at nodes. Foliage can be sticky. Flowers are funnel or bell-shaped and vary in color, though are most commonly seen in the pink range.

Caring for calibrachoa

Petunias and Calibrachoas should not be planted together in the same pots, as the Petunias will overwhelm the smaller Calibrachoas. Space plants between 8 and 12 inches apart for best coverage and airflow. Plant Calibrachoa in a space in the garden that receives full sun to partial sun. An average of six hours of sun will produce the best blooms. In warmer climates, make sure these herbaceous plants will receive some afternoon shade to avoid sunburn. These flowers will struggle in any conditions other than perfect drainage, and should be planted in areas that have light or nonexistent frost conditions. They do best in containers, but can also be planted in the ground. They prefer soil to be well-draining with a pH of between 5.0 and 6.5. They are quite pH sensitive, and will struggle outside of this range. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing.

Mulch around the base of plants to increase soil moisture retention, maintain constant soil temperatures, and to suppress weed growth. Water new plantings regularly as they develop a strong root system. Mature plants will need regular waterings for best performance. As a general rule of thumb, water whenever the top inch or two of soil feels dry to the touch. To fertilize, simply apply a dressing of compost around the base of the plant each year in springtime. Pull back mulch before applying, and replace after compost has been worked into the soil a bit. These plants do not require deadheading; spent blooms tend to fall off the plant naturally. If plants are grown in too much shade, they have a tendency to get a bit leggy. To avoid this situation, grow in more sun or prune plants to encourage a bushier habit. Calibrachoa plants are typically used as annuals, as they will die back with the first hard frost of the year. At the end of the growing season, pull plants and compost them. They can be replaced the next spring with new plants. In zones where Calibrachoa can be grown as perennials, they can last for a few years before needing to be replaced.

Propagation

Calibrachoa plants can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Trailing Petunia, follow the instructions below:

Propagating Calibrachoa by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new plant.

Propagating Calibrachoa by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed pods are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.