Quick Guide: Calibrachoa (Million Bells)

Calibrachoa is one of our most popular flowering annuals, and with good reason! This deer and rabbit resistant flower looks like a smaller petunia and is available in a plethora of colors and patterns. 

Calibrachoa has a trailing habit and is a very popular “spiller” when it comes to arranging flowers into containers. In fact, million bells thrive in containers even more so than in the ground. With good drainage and regular watering, million bells will continue to fill out your containers with color even as the nights get colder later in the fall. Calibrachoa is even frost resistant to an extent! Below is a short care guide to help teach you everything you need to know.

Million Bells are popular for their eclectic color varieties

Quick Facts:

Common Name

Calibrachoa, million bells, trailing petunia, mini petunia

Botanical Name

Calibrachoa group



Plant Type

Herbaceous perennial flower often grown as an annual

Mature Size

6–12 in. tall, 12–24 in. 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

Flower Color

Coral, yellow, orange, red, pink, blue, purple, burgundy, lavender, cream

Hardiness Zones

9–11 (USDA); grown as an annual in all zones

Native Area

South America

Sun Needs:

Calibrachoa bloom their best and fullest with at least six hour of full sun. If they receive less sun they run the danger of lighter and later blooms or no flowering at all. Browse other full sun annuals and start planning your next flowering arrangement. 

Million Bells can take twice a day watering especially if it is getting more than 6 hours of sun!


Million Bells can thrive in full-sun exposure, however they will require regular watering to make sure the sun doesn’t scorch them. This is especially true if you have baskets or containers. For the best growing conditions, the soil should be kept moist but not soggy.

Fertilizing Calibrachoa:

It is recommended that you fertilize your Million Bells hanging basket or container about once every two weeks with a general purpose plant fertilizer. As the season goes on, you may choose to start fertilizing weekly as more watering leeches the nutrients from the soil in the containers.

Other Needs:

Million Bells are considered a self-cleaning flower meaning that you do not need to dead-head them. Once the flowers have lived their life and died and dried up, their connection to the rest of the plant breaks down enough that a light wind can detach them naturally. This isn’t to say that you can’t pick off the dead and dried up flowers, but it isn’t necessary for the health of the plant.

Common Pests & Problems

Calibrachoa plants are a favorite of aphids. Don’t let that deter you from enjoying these colorful plants. Use water mixed with dishwashing detergent to help get rid of them. With tougher infestations you can use a product containing neem oil to clear them up.

Million Bells are extremely easy to take care of. There are just a couple of things to keep an eye out for:

  • Iron Deficiency – When iron deficient your plant will show a yellowing of new growth


  • Nitrogen Deficiency – Old growth will show yellowing when nitrogen deficient


  • Root rot – Caused by the decaying of roots due to overwatering and improper draining, root rot is one of the easiest ways to harm your million bells plants especially in containers and baskets. The best way to prevent this problem is through good air circulation, proper watering and proper drainage.