Calibrachoa, commonly known as Million Bells, is popular for its continuous color and cascading display. Its prolific, small, trumpet-shaped blooms appear from spring until the first frost. Its abundant flowers and relatively low maintenance make it a popular choice for containers, hanging baskets, and garden beds.
What Makes ‘Holy Smokes’ Unique?
Calibrachoa ‘Holy Smokes’ is a distinctive cultivar. Its elegant flowers feature a soft yellow base, overlaid with striking blue-purple splotches, often outlined in white, creating a multi-toned effect on each small, petunia-like bloom. This variety exhibits a mounding and trailing growth habit, typically reaching a height of 6 to 12 inches with a spread of 12 to 24 inches. Its compact nature and cascading stems make it an excellent choice for containers, window boxes, and hanging baskets.
Essential Care Requirements
Light
Calibrachoa ‘Holy Smokes’ thrives in locations that receive ample sunlight, at least six hours of direct sun daily. Full sun promotes abundant flowering throughout the growing season. While the plant can tolerate some partial shade, especially in hotter climates, insufficient light can lead to fewer blooms and leggy growth.
Watering
Consistent moisture is important, but avoid waterlogging to prevent root rot. Water the plant regularly, allowing the top inch or two of soil to dry out between waterings. In containers, especially during hot or windy weather, daily watering might be necessary to keep the soil consistently moist without being soggy.
Soil and Potting
Calibrachoa ‘Holy Smokes’ performs best in well-draining soil or potting mix rich in organic matter. They prefer a slightly acidic to neutral pH (5.5-6.5). For containers, use a high-quality potting mix. Proper drainage is essential, as Calibrachoa is sensitive to constantly wet feet.
Fertilizing
Calibrachoa ‘Holy Smokes’ is a heavy feeder and benefits from regular fertilization. Incorporate a slow-release granular fertilizer into the potting mix at planting time for sustained nutrient supply. Supplement this with a balanced, water-soluble fertilizer every one to two weeks throughout the growing season. A 20-10-20 N-P-K ratio is effective for healthy foliage and continuous flower production.
Temperature and Hardiness
Calibrachoa ‘Holy Smokes’ thrives in moderate temperatures, preferring 60-85°F (15-29°C). They are sensitive to frost and typically grown as annuals in most climates. In USDA hardiness zones 9-11, Calibrachoa can be treated as a short-lived perennial, surviving milder winters outdoors.
Pruning and Keeping Your Plant Full
Calibrachoa ‘Holy Smokes’ is a “self-cleaning” plant, naturally shedding spent blooms without manual deadheading. This simplifies maintenance and allows continuous new flower production. To encourage bushier growth and a more compact shape, pinch back stem tips. If the plant becomes leggy or overgrown, trimming it back by about one-third will promote new branching and a fuller appearance.
Regular pruning helps redirect the plant’s energy into producing more lateral shoots, leading to more flowers. This rejuvenates the plant mid-season and stimulates new blooms. Use sharp scissors or pruning shears for clean cuts, encouraging healthy regrowth.
Troubleshooting Common Problems
Yellowing leaves on Calibrachoa ‘Holy Smokes’ can indicate overwatering, nutrient deficiencies, or insufficient sunlight. If foliage turns light yellow with green veins, an iron deficiency might be the cause, often due to high soil pH. A general yellowing of older leaves may suggest a nitrogen deficiency, correctable with appropriate fertilization. Ensuring proper watering practices and consistent feeding helps prevent these common problems.
A lack of blooms is frequently tied to inadequate sunlight, insufficient phosphorus, or excessive nitrogen. While generally resistant, Calibrachoa can occasionally encounter pests like aphids or fungal issues such as root rot if overwatered.
Overwintering Your Calibrachoa
In regions with cold winters, Calibrachoa ‘Holy Smokes’ is typically grown as an annual. However, it is possible to overwinter container-grown plants indoors in USDA zones colder than 9. Before the first frost, bring the plant indoors and place it in a bright, cool location, ideally around 50-60°F (10-15°C), ensuring it receives at least four to six hours of light daily.
Prior to moving indoors, trim the plant back to a few inches and inspect it thoroughly for pests. During winter, reduce watering frequency, allowing the soil to dry out between waterings, and suspend fertilization as the plant enters dormancy. While overwintering is possible, many gardeners find it simpler to replace their plants with fresh ones each spring for optimal performance.