April 2014 Culture

Crop Culture Report: Euphorbia Princettia Series By Delilah Onofrey

Who says euphorbias have to be just for Christmas? Growers all over the world have been successful in promoting Suntory’s Princettia varieties outside the Christmas holiday season.

Available in four gorgeous shades of pink and Max White, Princettia is perfect for pink holidays, including Valentine’s Day, Easter and Mother’s Day. Another prime opportunity is October for Breast Cancer Awareness Month.

General Culture

Growers will find Princettia plants are naturally compact with excellent branching, producing many flowers without pinching. Princettias are a euphorbia hybrid, so many of the same cultural practices used to produce poinsettias successfully are the same. However, Princettia varieties are more compact with smaller bracts than most commercial poinsettia cultivars. Minor adjustments to culture should be made accordingly when Princettia varieties are produced with poinsettias.

Princettia varieties branch freely. In smaller container sizes, pinching is not a requirement. However, in larger containers (6 or 6.5 inch) pinching will produce a fuller plant. Consider using Cycocel after the pinch or the Florel sandwich technique before and after pinch to enhance uniform branching. If Cycocel or Florel are used, monitor height closely after the application. This may be the only time plant growth regulators are needed throughout production.

The bracts and leaves of Princettia are also smaller than traditional poinsettias. Because of the smaller bract size, it is not recommended to grow Princettia using cold-grow techniques that can be used for some poinsettias. Grow and finish Princettia warm to produce the highest quality plants.

Watering

Because Princettia varieties are compact,
irrigation frequency should be adjusted to reflect the slower growth rate. Monitor root health and avoid overwatering.

Lighting

Princettia varieties are photoperiodic. Depending on the time of year plants are produced, photoperiod manipulation with lighting or black cloth will be necessary.

Crop Timing

• 4-inch pot – one liner, 10 weeks
• 6-inch pot – one liner, 20 weeks

Temperature

Recommended temperatures:

• Propagation – Day 76 to 82_ F/Night 70 to 74_ F
• Growing On – Day 80 to 82_ F/Night 70 to 72_ F
• Finishing from short days – Day 72 to 75_ F/ Night 65 to 68_ F
• Temperatures can be adjusted to change the rate of flower development; however, night temperatures should never go below 62_ F.

Feeding

Fertility needs are very similar to poinsettias; however, due to the compact nature of Princettia, monitor EC of the media closely to ensure the rate of fertilizer is not too high compared to the growth rate. Ideally, the EC should range from 5.8 to 6.2 mmhos/cm. Consider using 250-ppm 15-5-15 cal/mag complete with micro nutrients.

Growth Regulators

Princettia varieties are much more compact than most commercial poinsettia cultivars. In most cases, plant growth regulators will not be needed. In larger product forms, additional vegetative growth should be added

If height control is needed, Princettia responds very well to B-Nine/Cycocel in propagation and Cycocel alone after transplant. Consider the following rates:

• Propagation – B-Nine 1000 ppm/Cycocel 1000 ppm
• After transplant – Cycocel 750 to 1250 ppm
• Do not apply Cycocel after the sign of first color.

Pests & Diseases

Insect pests and diseases that impact poinsettias also impact Princettia. Monitor closely for whiteflies and watch root health throughout production. As flowers develop monitor for botrytis.

SIDEBAR

Off-Peak Promotional Opportunities

In Japan, 8,000 retailers sell Princettia at a premium in the fall. These include high-end florists, department stores and nontraditional outlets for plants. Hello Kitty created a special edition Princettia doll as part of the promotion and sold plants in the stores. Average wholesale price is double that of a Christmas poinsettia. Just last fall, Princettia partnered with New Balance to sponsor a charity Run for the Cure in Tokyo. Plants were displayed on site and given to those who contributed to the cause.

In Australia, leading grower Oasis Horticulture supports the National Breast Cancer Foundation through Princettia plant sales. Princettia was bred in Australia through Bonza Botanicals, a joint breeding venture between Suntory Flowers and Oasis Horticulture. European markets have also been successful with Princettia. The same strategies could be used in North America. Just be sure to promote the Princettia brand as a truly differentiated product.