Calibrachoa, also known as million bells, is one of the most popular plants for growing outdoors in containers. The plant comes in a rainbow of colors, in solids and two-tones, stripes, patterns, and stunning double blooms. Calibrachoa is a prolific bloomer and produces 1-inch blossoms that resemble tiny petunias. The compact leaves are oval-shaped and a bit sticky.

In most growing zones, million bells is best planted or repotted in the spring. It can bloom continuously through the growing season until first frost, and its flowers attract butterflies and hummingbirds.  It's also a fast grower and quickly reaches toward the ground as a "spiller" when grown as a container plant. Because of its trailing habit, it looks great in hanging baskets, bowls, or mixed containers. It also works well planted in-ground as a border plant.
Calibrachoa Care
Although it is a short-lived perennial in very warm climates, Calibrachoa is grown almost everywhere as an annual. The plant is not hard to care for, but paying attention to its needs will keep it blooming from spring well into fall. While it can be planted in garden beds, the plant fares much better in containers.
This is considered a “self-cleaning” plant, meaning it doesn’t need to be deadheaded to keep blooming; however, it will benefit from a serious cutting back toward the end of summer, along with a boost of fertilizer to reenergize the plant. Deer don't seem very interested in Calibrachoa, although it is not classified as deer-resistant.
Common Name Calibrachoa, million bells, trailing petunia, mini petunia
Botanical Name Calibrachoa group
Family Solanaceae
Plant Type Herbaceous perennial flower often grown as an annual
Mature Size

15-30 cm (6"-12") tall, 30-61 cm (12"-24") wide

Sun Exposure

Full sun to part shade

Soil Type

Moist, rich, well-drained

Soil ph

5.0-6.5 (acidic)

Bloom Time

Spring to Fall

Native Area South America


The plant blooms best with at least six hours of full sun, but it can tolerate partial shade—especially in warmer areas, where plants that get some shade are likelier to survive through the summer months. Insufficient sun exposure typically results in reduced blooming.


Calibrachoa likes fast-draining potting soil, so make sure your pot has good drainage. When planting in garden beds, amend with organic material to ensure richness, and make sure the soil drains well. Mulch is recommended to keep the soil moist and the root system cool.


Calibrachoa needs to be kept well hydrated but not water-logged. Add water only after the top inch or so of the soil dries out. To check if your plant needs water, stick your finger into the soil up to the second knuckle. If the soil feels dry at your fingertip, water deeply until it drains out of the bottom of your pot. Don’t water again until the soil dries out again.

Heat, wind, and lack of humidity can cause your soil to dry out quickly. Depending on your conditions, you may have to water as often as twice a day. Check the soil frequently, especially at the beginning of the season, until you get to know your plant's needs; watering requirements may change as the summer heats up. Take care not to overwater the plant, as this can encourage root rot.

Temperature and Humidity

The plant is pretty drought and heat tolerant, and even cold-tolerant, but to get the best blooms, don’t let it dry out repeatedly. It prefers temperatures between 12 and 19 degrees Celsius. A hardened-off plant can be brought outdoors in the spring months, and it can tolerate a mild frost. At the other end of the spectrum, hot weather and dryness can be stressful to the plant. You can revive wilted foliage with a daily misting, but be careful not to mist in direct sun, as this can burn the leaves.


This plant is a heavy feeder that can be fed with a slow-release fertilizer at planting and/or a diluted liquid fertilizer regularly. For example, you can start with an organic, slow-release fertilizer mixed into your potting medium, and then give the plant a diluted liquid every couple of weeks throughout the season. Feeding is particularly necessary near the end of the season to promote late blooms. Be careful not to over-fertilize—follow the directions on the label of the plant food closely. Leaves turning light green or yellowish is a sign that the plant needs fertilizer, or possibly more sun.