Secrets of producing Million Bells Calibrachoas

Million Bells

Looking for carefree color? Million Bells are versatile plants that are suited to hanging baskets, patio containers, window boxes and landscapes. Suntory Flowers breeders Yasuyuki Murakami and Kenichi Suzuki are the fathers of the entire calibrachoa genus for commercial production worldwide. Twenty years later, calibrachoas have become a major crop in every vegetative annual program.

Suntory continues to reinvest and improve the series, which now spans 12 mounding types, seven trailing and the newer Bouquet subseries, which appeals to growers looking for more compact varieties for high density production. The original trailing types are still very popular because of their vigorous growth, profuse blooming and ability to create lush, cascading displays in hanging baskets.

Calibrachoas are annuals in Zones 2-8 and can be perennials in Zones 9-12. Heat and cold tolerant, Million Bells will produce flowers from spring well into fall. Each summer, Million Bells stands out among hundreds of calibrachoas to earn high marks in leading university trials.

General Culture
While at first glance, Million Bells look like little petunias, the cultural requirements are significantly different. Calibrachoa is a facultative long-day plant, although modern breeding has made great advances in bringing the flowering time forward. Provide long days during propagation and production, if possible.
Once cuttings are rooted and established, liners can be given a pinch to encourage a bushy plant. This is usually around three to four weeks after sticking. If this is not done by rooting stations, it should be done by the grower at potting or just afterwards. As the crop grows, it may require more pinching to encourage the right habit and breaks to get bushy, spreading plants.

pH Management
Rooted cuttings should be potted as soon as possible into 4-inch or larger pots, using a well-drained peat/perlite mix. Keep pH at 5.2 to 6.0 to prevent disease and nutritional problems. The key is to keep the pH down to help prevent Thielaviopsis root rot, which is less persistent in media with a lower pH. Many growers use an acid feed with added iron based on a soil test to accomplish this. Calibrachoas respond well to added iron.
Watering
Avoid overwatering Million Bells. Watering is a key issue because high levels will encourage root rot. A little-and-often regime is encouraged when plants are young to provide as much air to the crop as possible.
Temperature
Start Million Bells warm then finish cool after they are well established. For the first two weeks, keep temperatures between 65-75°F to enhance root development. After two weeks the crop is best grown at 60-65°F.
Crop Timing
• 4-inch production – four to six weeks with one liner and one or two pinches
• 6-inch production – six to eight weeks with one liner and two pinches
• 10-inch production – 10-12 weeks with three liners and two or three pinches
Growth Regulators
Million Bells respond to sprays of B-Nine (2,500-5,000 ppm) or Sumagic (5-20 ppm). Another option is a Bonzi drench (2-3 ppm). Some growers find it effective to use Bonzi later in the season at a lower dose multiple times.
Pests & Diseases
Insect pests to monitor include whitefly, western flower thrips, aphids and red spider mites. Diseases to prevent include Botrytis, Powdery Mildew, Phytophthora, Rhizoctonia, Pythium and Thielaviopsis. Growers find using an aggressive, preventative fungicide drench to be worthwhile in establishing the crop and maintaining it.

For more crop-specific production advice from Suntory Flowers, download the Grower’s Guide App in the iTunes store.