Calibrachoa, commonly known as Million Bells, is a versatile flowering plant belonging to the Solanaceae family, also known as the nightshade family. They are a very popular annual plant at Martin Garden Center. The flowers of Calibrachoa bear a resemblance to those of traditional petunias, leading to another nickname, “Mini Petunia.” They tend to have a trailing habit, making them a perfect addition to container baskets. With its abundant and colorful blooms, Calibrachoa brings vibrant beauty to any landscape.
Size and Shape of Calibrachoa
Calibrachoa plants typically have a compact and trailing growth habit. The size and shape of Calibrachoa plants can vary depending on the variety and growing conditions. On average, they reach a height of 6 to 12 inches and spread up to 18 to 24 inches. The trailing stems can grow several feet long, making Calibrachoa ideal for hanging baskets, window boxes, and containers. They form cascading mounds of lush foliage and produce numerous small, trumpet-shaped flowers.
Caring for Calibrachoa
Calibrachoa thrives in full sun or partial shade. However, it performs best when exposed to at least 6 hours of direct sunlight daily. Providing some afternoon shade in hotter regions can help protect the plant from scorching. Calibrachoa is a warm-season plant and prefers temperatures between 60°F and 85°F (15°C and 29°C). It is not frost-tolerant and should be protected from cold temperatures.
Well-draining soil is crucial for the healthy growth of Calibrachoa. A lightweight potting mix enriched with organic matter works well for container gardening. In garden beds, amend heavy soil with compost or organic matter to improve drainage. Calibrachoa requires regular watering to keep the soil consistently moist but not waterlogged. Ensure the soil is evenly moist, especially during hot and dry periods. Avoid overwatering, as it can lead to root rot and other problems.
Regular fertilization is essential for continuous blooming. We recommend Fertilome Garden Cote 6, which provides a slow-release six-month feed. Supplement occasionally with a high-phosphorous fertilizer such as Jack’s Blossom Booster for more blooms. Also, periodically trim back Calibrachoa’s leggy or overgrown stems to maintain a compact and bushy shape.
Propagating Calibrachoa
Calibrachoa can be propagated via Seeds and Cuttings if you wish to multiply your plant collection or share with fellow gardeners.
- Seeds: Calibrachoa seeds are tiny and can be challenging to handle. Start by sowing the seeds indoors 8 to 10 weeks before the last frost date. Use a well-draining seed-starting mix and lightly cover the seeds with a thin layer of soil. Keep the soil moist and maintain a warm temperature around 70°F (21°C). Once the seedlings develop several sets of true leaves, they can be transplanted into larger containers or outdoor garden beds.
- Cuttings: Taking cuttings from established Calibrachoa plants is a popular and reliable propagation method. Select healthy, non-flowering stems and make clean cuts just below a node. Remove the lower leaves, leaving only a few at the top. Dip the cut end in a rooting hormone powder to encourage root development and place the cutting in a well-draining potting mix. Keep the soil consistently moist and provide indirect light. Once roots have developed, transplant the rooted cuttings into individual pots or garden beds.
Calibrachoa Diseases: Common Issues and Prevention
Like any plant, Calibrachoa is susceptible to certain issues and diseases. Overwatering or poorly drained soil can lead to root rot. To prevent this, ensure proper drainage, use well-draining soil, and allow the top layer of soil to dry slightly between watering. Calibrachoa is also susceptible to powdery mildew, a fungal disease that appears as a white powdery coating on leaves. Provide good air circulation, avoid overhead watering, and remove affected plant parts promptly. Fungicidal sprays may be necessary in severe cases.
Botrytis blight, or gray mold, causes fuzzy grayish-brown spots on flowers and leaves. Improve air circulation, space plants adequately, and remove any infected plant material. Fungicidal treatments can be used as a preventive measure. Calibrachoa is also susceptible to Aphids and Spider Mites: These common pests can infest Calibrachoa plants, causing damage to leaves and flowers. Regularly inspect plants and use insecticidal soap or neem oil to control infestations. Encouraging natural predators like ladybugs can also help keep these pests in check.
Calibrachoa vs. Petunia
Calibrachoa and petunias are often associated with each other due to their similar appearance and shared family. However, there are some notable differences between these two flowering plants.
- Growth Habit: One of the primary distinctions between Calibrachoa and petunias lies in their growth habit. Petunias have a more upright and bushy growth pattern, while Calibrachoa exhibits a trailing or cascading habit. This makes Calibrachoa an excellent choice for hanging baskets, window boxes, and containers where its trailing stems can spill over the edges, creating a beautiful cascading effect.
- Flower Size: Another noticeable difference is the size of the flowers. Petunias typically produce larger blooms, ranging from 2 to 4 inches in diameter, while Calibrachoa flowers are smaller, typically around 1 inch in diameter. However, what Calibrachoa lacks in size, it makes up for in quantity, as it produces an abundance of blossoms that completely cover the plant, creating a stunning carpet of color.
- Color Range: Calibrachoa and petunias offer an extensive range of vibrant colors. However, Calibrachoa is renowned for its intense and vibrant hues, often featuring bright oranges, yellows, pinks, and purples. On the other hand, petunias come in a broader spectrum of colors, including pastels, bicolors, and even striped or speckled varieties. Petunias also offer more options for solid white or solid black flower varieties.
- Weather Tolerance: Calibrachoa is known for its excellent heat tolerance and ability to withstand hot and dry conditions. It thrives in full sun and is well-suited for warmer climates. Petunias, while also able to handle the heat, may be more prone to wilting and require regular watering during scorching summers.
- Maintenance: Both Calibrachoa and petunias are relatively low-maintenance plants. However, Calibrachoa requires more frequent watering due to its smaller root system and faster-drying soil. Petunias are generally more forgiving when watering, as they have more extensive root systems. Regarding deadheading, both plants benefit from removing spent flowers to encourage continuous blooming throughout the season.
Varieties of Calibrachoa
At Martin Garden Center, we grow a thousand plus Superbells each year, plus we also grow many of the Colibri, Callie, and MiniFamous series of million bells. Some of our favorites include MiniFamous Neo Violet Ice, Colibri Cherry Lace, Callie Eclipse Lavenders, Superbells Pomegranate Punch, Superbells Holy Moly, Superbells Sharon, Superbells Tangerine Punch, and the list goes on and on.