Grow it Now: Producing SuperCal® in Quarts

Technical Support Specialist Bob Croft Tells You How

SuperCal is an innovative class of petunia with two great parents (petunia x calibrachoa) that combine to create a remarkable plant. Their exceptional garden performance demonstrated in trials throughout North America have earned SuperCal and SuperCAl Premium the title “All Weather Petunia®”

SuperCal is less likely to show iron chlorosis, due to high pH, and has a very strong root system that helps leaves stay greener under stressful conditions. Excellent vigor, large flowers and ease of growing make SuperCal ideal for baskets, beds, borders and mixed containers.   The unique flower colors are intense and the blooms hold up well even under severe rainy weather. Vibrant flowers contrast nicely with lush green, non-sticky foliage to maintain a fresh, clean look without additional maintenance.

All these traits synergize into exceptional garden performance enhancing your customer’s experience. SuperCal thrives under cool environments and conditioned plants can tolerate temperatures of 28 to 30°F/-2 to -1°C with no damage to the foliage. As the heat of summer rises and takes its toll on most cool season annuals, consumers will find that SuperCal outperform traditional calibrachoa and petunias with stronger blooming power.

Many growers have experience with producing SuperCal in hanging baskets and mixed containers and are also looking to produce plants in smaller pots to meet market demand.   Sakata created the following guidelines to assist growers with producing high quality 5-inch / 1 Quart pots.

Variety Selection: SuperCal Artist Rose, Blue, Blushing Pink, Cherry, Crimson Red, Light Yellow, Pink, and SuperCal Premium Bordeaux, Caramel Yellow, Cinnamon, French Vanilla and Sunray Pink are recommended for quart production due to plant habit and less need for supplemental lighting.

Additional Notes

  • Start with a uniform cutting about ½ to ¾ inches/1.25 to 2 cm. long and 2 sets of leaves.
  • Pinching: Some additional shaping of plants may be needed to provide an ideal finished plant.
  • Temperature: Cooler temperatures (55-60°F/13-16°C) combined with high light (>5,000 fc) produce high quality plants. However, crop time will be longer by a few weeks with significant lower average daily temperatures.
  • The use of a retractable roof greenhouse for full light exposure during the day and frost protection at night is ideal.
  • PGR’s: Florel must be applied early in the crop (at least 8 weeks prior to shipping) to prevent flower delay.

Production Week




  • Direct stick cuttings into an 84 to102-cell tray filled with a sterile, well-drained and porous media. Moisten the soil prior to sticking. (Do not soak the soil).   pH 5.0-6.0.
  • Keep media on the moist side, but not saturated as excess moisture slows rooting.
  • Under less than ideal conditions, consider using a rooting hormone with up to 2500 ppm of IBA. Mixtures that also include up to 500 ppm of NAA work as well.
  • Bottom heat enhances root development. Maintain soil temperature between 68-72°F/20-22°C.



  • Cuttings should require mist for 5-7 days and then only as needed to help keep cuttings turgid and prevent wilting
  • Maintain moderate humidity (50-60%) and Light levels around 1,500-2000 fc
  • A preventative soil drench for Pythium may be applied to assist with root development
  • After 3-7 days from sticking, remove from mist and apply a tank mix spray of 500* ppm Florel (ethephon) and 1250-2500ppm B-Nine. Apply early in the day to allow maximum absorption. (*A lower rate of 250 ppm Florel and 1250 B-Nine is recommended on Vanilla Blush.)




  • Pinch liners if excess stretch has occurred during propagation, and transplant into 1-quart pots filled with a sterile, well-drained and porous media. (pH 5.0-6.0.)
  • Maintain temperature 70o-60o F/21-16°C (day/night) and relative humidity around 50-60%
  • Increase light level to 3500-5000 fc (avoid growing baskets overhead)
  • Allow media to dry in-between irrigations to tone plants and maximize uptake of nutrients.
  • Following root establishment, use constant liquid feed at 100 ppm N with a full minor complement*. (Cal-Mag/low ammonium fertilizer such as 15-5-15 work best)
  • Supplemental applications of magnesium sulfate (MgSO4) at 8 ounces in 100 gallons/ 60 grams in 100 liters every 2 weeks are recommended to promote a deep green leaf color.
  • Target the EC level at 1.0 to 1.5 mmhos (2:1 slurry).
  • As plants begin to fill-in (7-8 weeks after sticking) apply B-Nine spray at 2,500 ppm to help maintain a bushy habit. A second application may be required 2-3 weeks later.

*Fe 1 ppm, Mn 0.5 ppm, Zn 0.5 ppm, B 0.25 ppm, Cu 0.25 ppm, Mo 0.1 ppm



Finish (11-15)

  • A Bonzi (paclobutrazol) drench at 2-5 ppm works well to finish the plants and prevent excess stretching 1-2 weeks prior to shipping.
  • Maintain average daily temperatures of 65oF/18oC.
  • Be sure to tone plants with high light (>5000 foot candles) but maintain the fertilizer at full strength to keep the foliage dark green and healthy.