Calibrachoa is a genus of exactly 28 species of gorgeous flowering plants that look very much like the well-known Petunias. In cultivation, the flowers from this genus go by various common names, such as Million Bells, Super Bells, Mini Petunia, or Trailing Petunia. Calibrachoa is a member of the Solanaceae (nightshade) family.
Calibrachoa plants are more than a delightful view. These beauties are among the most popular garden ornamentals that thrive outdoors in pots. Wondering what makes Calibrachoa plans so popular among gardeners worldwide? Besides looks, what most growers appreciate about these plants is their ability to thrive with little to no effort on their part. Calibrachoa plants will have a nice time almost anywhere you place them, tolerating a wide range of environmental conditions.
Are you ready to learn more about Calibrachoa a.k.a. “Million Bells” flowers? Keep reading!
- Calibrachoa plants come from the same region of South America as Petunias. Their native habitat ranges from southern Brazil through Chile and Peru. Calibrachoa plants usually inhabit scrub and open grasslands.
- Calibrachoa plants come in many different colours and there are plenty of unique cultivars. Some of these are C. ‘Cabaret’ series (Coral Kiss, Deep Blue, Yellow, Light Pink, Orange, Pink Star, Sky Blue, and White) and C. ‘Superbells’ series (Holly Moly!, Miss Lilac, Lemon Slice, Hollywood Star, Plum, Tropical Sunrise, Blue Moon Punch, Double Orchid, etc.).
- The Calibrachoa cultivars ‘Cabaret Bright Red’, ‘Calibasket Pink Doll’, ‘Million Bells Trailing Topaz’, ‘Minifamous Double Light Blue’, ‘Minifamous Double PinkMania!’, ‘Rave Pink’, and ‘Superbells Pink’ have gained the prestigious Award of Garden Merit.
- Due to their overall trailing habit, Calibrachoa plants are excellent choices for hanging baskets, raised beds, mixed containers, or bowls to provide that cascading effect. They are also a nice addition as border specimens planted directly into the ground.
- Being fast-growing plants, Calibrachoas are often referred to as ‘spillers’ because their flowers tend to spill out of their containers. Their beautiful blooms make Calibrachoas perfect additions to cottage gardens.
- Calibrachoa plants can make for eye-catching companions to other fabulous species of plants. These include Petunias, Licorice Plant, Baby’s Breath, Purple Fountain Grass, Salvia, Geranium, Persian Shield, and African Daisy.
- They belong to the same plant family as the toxic Nightshades, so these plants may have toxic effects on both humans and pets if ingested. For safety purposes, plant them in an area where curious kids or animals cannot reach them.
- Calibrachoa flowers attract beneficial pollinators such as butterflies, bees, and even hummingbirds. It is deer-resistant as most gardeners have noticed that deer don’t find these plants interesting.
Calibrachoa Features: An Overview
- Calibrachoa plants are small shrubs and evergreen herbaceous plants. They are bushy, compact, and typically have a short lifespan, but can behave as both annuals and perennials.
- These buddies can reach from 6 to 12 inches (15-30 cm) in height and 12 to 24 inches (30-60 cm) in width. With time, Calibrachoa plants will trail up to 30 inches (75 cm) in length.
- Their foliage contains numerous leaves that vary depending on the cultivar. The leaves can be either ovate, linear, reverse ovate, or elliptic. They have flat or rolled back edges and grow on woody, greenish stems.
- In general, Calibrachoa plants bloom from late spring to the first frost. During this generous period, the plants produce masses of delicate, funnel-shaped, petunia-like flowers.
- Their blossoms come in a very generous colour palette. They can exhibit lots of white, yellow, orange, pink, red, lavender, burgundy, blue, purple, coral, and cream shades. Most varieties have hypnotic flowers in at least two of these shades.
- Calibrachoa plants may produce fruits once their blooming season has ended. The fruits are capsules that feature several seeds with an interesting net-like surface.
- Because Calibrachoas and Petunias are quite similar, you might have a hard time telling them apart. The main difference between Petunias and Calibrachoas are their flowers – Calibrachoas have smaller flowers than Petunias. In addition to that, Calibrachoas are generally considered easier to grow than Petunias.
Growing and caring for Calibrachoa plants can be a piece of cake as long as you pay attention to their basic needs. They are not as picky as you might expect and their demands are not hard to meet. The important thing to remember is the fact that you will have to care for your Calibrachoa plants properly if you want them to reward you with their spectacular flowers.
Calibrachoa plants require as much sunlight as you can possibly offer them. These flowers will perform best with at least six hours of bright and direct light daily. If you cannot provide your Calibrachoa plants with this amount of light exposure, no worries! Calibrachoa plants can also do just fine in partial shade for a while, especially in areas with warmer climates.
What makes Calibrachoa plants one of our favourite ornamentals is their general easy-going nature. These friendly ornamentals can tolerate drought, heat, cold temperatures, and even mild frost. However, this does not mean that you growing your plants in extreme conditions won’t be a challenge. Calibrachoa plants prefer average humidity levels and temperatures that range from 55 to 65 °F (13-18 °C).
In most climates, Calibrachoa flowers should be planted or repotted in spring and they will have a long blooming period.
When you first buy Calibrachoa plants, they will generally come badly root-bound. This particular situation will give your plants too little soil to grow in, affecting their overall performance with time. Because of this, we recommend you transplant your Calibrachoa plants in new containers so their root balls will experience optimal conditions. Moreover, you should add a slow-release fertilizer into the all-purpose potting soil to spoil your plants with nutrients.
- SUN: The plant blooms best with at least six hours of full sun, but it can tolerate partial shade. Insufficient sun exposure typically results in reduced blooming.
- SOIL: Calibrachoa likes fast-draining potting soil, so make sure your pot has good drainage. Mulch is recommended to keep the soil moist and the root system cool.
- WATER: 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.
- WHEN TO PLANT: Calibrachoa is best planted or repotted in the spring. It can bloom continuously through the growing season until the first frost.
- PLANTING SUGGESTIONS: This plant is a heavy feeder that can be fed with a slow-release fertilizer at plantingand/or a diluted liquid fertilizer regularly.
- LIGHT & SOIL: It is easily grown in moist, organically rich, well-drained soils in full sun. Tolerates very light shade, but flowering decreases as the amount of part shade increases.
- TALL: Grows up to 3-9'' tall, and 6-24'' wide.
- BLOOM PERIOD: These plants are prolific bloomers that produce hundreds of 1” wide flowers from spring to frost.
- USES: Best in hanging baskets, containers or as a small area ground cover. Also may be used in border fronts or rock gardens.
- USDA ZONE: Tender perennial that is winter hardy to USDA Zones 9-11.
- LIGHT & SOIL: Select a location in full sun to light shade with good rich moist organic soil. Calibrachoa prefer a pH of 5.5 to 6.0.
- SOW: Sow seeds thinly and barely press into seed starting formula as seeds benefit from light to germinate.
- GERMINATION: Keep the soil moist at 70-75 degrees. Seedlings emerge in 10-14 days.
- REPOTTED: Transplant hardened-off seedlings to the garden after all danger of the frost.
- BLOOM PERIOD: Calibrachoa blooms from July until frost.
Last update on 2024-02-02 / Affiliate links / Images from Amazon Product Advertising API
If you plan on growing your Calibrachoa plants in containers, choose pots that come along with drainage holes at the bottom. In terms of growing medium, a substrate that is moist, rich in organic matter, and features very sharp drainage is more than ideal. The soil pH should be somewhere in-between 5.0 and 6.5 (acidic). Mulch is also a good option if you want to keep the root system of your Calibrachoa plants cool and the soil’s moisture at suitable levels.
Calibrachoa plants are heavy feeders that will thrive with regular fertilizing during their period of interest, from spring through fall. As mentioned above, a slow-release, organic fertilizer mixed in the potting soil is what you should begin with. After this, you must feed your Calibrachoa plants with a diluted liquid fertilizer once every couple of weeks. A secret tip – feeding is most important near the end of the season, in autumn, to promote late flowering.
Although Calibrachoa plants do not need deadheading to bloom properly, they will benefit from a pruning session once every year. At the end of the summer, you should opt for a serious cutting back for your plants to keep them fresh and vigorous. After this process, a boost of fertilizer is mandatory to bring the energy back to your plants.
When it comes to watering, you should know that Calibrachoa is a big lover of moisture. Still, soggy conditions or waterlogging is not an option for these plants. If they receive more water than needed, you might encounter serious problems, such as fungal infections and root rot. But keep in mind that you can always avoid this from happening with one single technique!
Make sure you provide your Calibrachoa plants with water only when the top inch (2.5 cm) or so of their growing medium has dried out completely. When the time is right, water your plants until the water drains out of the bottom of their pots.
The frequency of watering Calibrachoa plants may vary from one season to another. In other words, extreme heat, strong winds, or low humidity levels will typically cause their soil to dry out faster. If this happens, you might need to water your plants even as often as twice a day. But do not forget about the first-inch rule! It is always a good idea to check the soil before adding water. If the first inch of soil is completely dry, it’s safe to water your plants.
As previously mentioned, when buying a potted Calibrachoa you should expect it to be root-bound which means that the plant has a large root system and doesn’t have a lot of soil in its container. Plants that are in this situation should be repotted in larger containers. Calibrachoas that are root-bound are more susceptible to overwatering and will be nutrient-deficient. So, when you repot a freshly-purchased Calibrachoa, take it out of its original container and loosen the root ball before replanting it. Use a general-purpose potting mix and add slow-release fertilizer. You can use any type of container as long as it has drainage holes.
Since most Calibrachoa plants you can find in nurseries are hybrids, they will not produce as many seeds as a regular species. Plus, the few seeds also have an extremely low chance of success and you might not get the exact same cultivar. But if you want more specimens of the exact Calibrachoa hybrid you already have, you don’t need to spend more money on another one. The good news is you can easily make more of these stunning flowers by propagating them through stem cuttings.
First things first, look closely for stems that have small buds on them, but not flowers. Once you find them, you can cut about 6 inches (15 cm) of them using a sharp, sterilized cutting tool. Remove the lower leaves from each cutting, as the roots will generally emerge from the spots in which the leaves were before.
Fill a container with a mix of equal parts of potting soil and peat moss. Plant the cuttings in this substrate and add water until it drains out of the pot. Place the container in a location where the cuttings can receive lots of bright light. Make sure the cuttings experience constant moisture and warm temperatures. With proper care, your Calibrachoa cuttings will begin to develop a root system after a couple of weeks or so.
Calibrachoa Pests and Diseases
Now, we need to speak about how susceptible Calibrachoa plants are to pest infestations, especially aphids. These pests will damage the foliage and sometimes the flowers of your beloved plants if you do not take action. Aphids hide on the underside of leaves and cover the plant in a sticky substance called ‘honeydew’. If you notice any suspect presence on your Calibrachoa plants, it’s best to take action and to wash the intruders off. You can use plain water, a mix of water and dish soap, or neem oil. You can learn more about this process from our complete guide to removing aphids.
It is important to mention that the leaves of Calibrachoa plants are naturally sticky, so you shouldn’t be alarmed by this feature unless you also notice the presence of aphids.
Another common issue that growers might encounter while growing and caring for Calibrachoa plants is yellowing leaves. This symptom can indicate several potential problems including an iron deficiency, a nitrogen deficiency, or a fungal infection and root rot. Iron deficiency will usually manifest as yellowing new foliage, while nitrogen deficiency will trigger yellowing old foliage.
Root rot and mould infections are usually caused by overwatering and can easily be avoided if you use the ‘soak and dry’ watering schedule. With good drainage and proper water management, these diseases can easily be avoided.
If you love flowering ornamentals but are the type of gardener that wants to spend as little time as possible caring for your companions, Calibrachoa plants are perfect for you! These flowers are prolific bloomers and they require less attention than other regular ornamental plants. It is safe to say that the longest time spent with Calibrachoa plants will probably be the part where you pick your favourite cultivar for your collection.
Are you growing Calibrachoa plants? Share your experience in the comment section!