Million Bells Plant Profile

million bells

The Spruce / Autumn Wood 

Million bells (Calibrachoa) is an annual flower that's planted in the spring in most growing zones and blooms nonstop from spring to frost without the need for deadheading. It is most commonly grown in containers or hanging baskets, where it spills gracefully over the sides with a dense trailing habit rather than a spindly one. Million bells plants also attract hummingbirds and butterflies. The blooms are approximately 1 inch across, and many sport veining or colorful throats that contrast with the primary petal color. The foliage is bright green, oval, and compact.

Botanical Name Calibrachoa
Common Name Million bells, trailing petunia, mini petunia
Plant Type Herbaceous perennial, annual
Mature Size 3 to 9 inches tall and 6 to 24 inches wide
Sun Exposure Full sun
Soil Type Rich, moist, well-draining
Soil pH 5.2 to 6
Bloom Time Spring to frost
Flower Color Pink, yellow, red, violet, white, blue, magenta, bronze
Hardiness Zones 9 to 11
Native Area South American hybrid
million bells
The Spruce / Autumn Wood
million bells in a hanging container
The Spruce / Autumn Wood 
multi-colored million bells
Hidestugu Mori / Getty Images

How to Grow Million Bells

Million bells plants are tender perennials in zones 9 to 11. But most gardeners treat them as annuals and plant them after the danger of frost has passed in the spring. Ample sunlight and rich, moist soil are key to their growth.

Their trailing habit and prolific blooms make them excellent candidates for container gardens. Million bells plants are also somewhat drought-tolerant, so you can include them in a rock garden where they will appreciate the sharp drainage conditions. If you use million bells as a ground cover, keep in mind that the plants seldom spread more than 2 feet, so plant enough to ensure adequate coverage.


Million bells flowers grow best in full sun. Dappled shade or afternoon shade are second-choice placements in the garden, but this might turn your “million bells” into “hundred bells” due to a reduction in blooming.


Fill your planting containers with soilless potting mix amended with humus or compost. Potting mix will ensure the excellent drainage necessary for plant health, as million bells hates soggy soil

If you are growing the plants in the ground, plant them in rich, well-draining soil with a slightly acidic pH of 5.2 to 6. Space the plants about 18 inches apart to allow for spreading. Cover the soil with organic mulch to keep the root system cool and to stop evaporation.


Keep the plants evenly moist, and don't ever let the soil completely dry out. Do a "swing test" daily if you have hanging baskets: Does the basket seem light when you give it a push? If so, you must irrigate until water flows through the drainage holes. If you're using pots or other containers, test the soil moisture by inserting your finger up to the second knuckle. If the soil at your fingertip feels dry, it's time to water. Add water until it comes out of the container's drainage holes. And continue to test the soil regularly to keep on top of watering needs.

Temperature and Humidity

Million bells plants thrive in warm weather, but they can become heat-stressed. If you live in a dry climate, you can try misting the plants daily or as needed to increase humidity and revive the foliage. But do not mist in direct sunlight, which can lead to leaf burn.


Fertilize your million bells every two weeks throughout the growing season with a liquid flower fertilizer, which provides nutrients more quickly than time-release formulas. This is especially important at summer's end to coax more blooms out of the plants. If your million bells plants have light green or yellowish foliage, this is also a symptom that they need a nutrient boost (or more sunshine). 

Growing From Seeds

The majority of million bells plants on the market today are hybrids that are vegetatively propagated, so you must grow these from plants rather than seed. However, the 'Kabloom' series offers gardeners an economical way to grow million bells from seed with the same self-cleaning habit and prolific blooms of other varieties. The trade-off is a significant waiting period, as it takes about four months from sowing to bloom for these plants. The seeds need light for germination, which takes about two weeks.

Common Pests and Diseases

If you plant your million bells too early in the spring, they might fall prey to aphids. To prevent this, plant them outdoors around the same time you'd plant tomatoes in your area.

Whether they're grown in containers or in the ground, keep your plants from becoming heat-stressed, which can tempt spider mites. If the weather conditions are dry and dusty, practice cultural control of these pests by misting plants with water daily.

Furthermore, unlike petunias, million bells don’t suffer from the dreaded tobacco budworm. 

Varieties of Million Bells

Million bells is the most well-known hybrid in the Calibrachoa genus. Within this group, there are many varieties and colors to choose from, including:

  • 'Kabloom': Seeds available in pink, white, red, yellow, and deep blue
  • 'Crackling Fire': Dark neon orange flowers marbled with yellow
  • 'Tangerine': Cheerful clear orange flowers with red veining
  • 'Terra Cotta': Yellow flecked with red
  • 'Trailing Sky Blue': Bright lavender-blue flowers with green throats
  • 'Cherry Pink': Hot pink flowers with yellow throats; a hummingbird beacon