The Water Cube, where Michael Phelps won a record eight gold medals, was the place to be at the Olympics in Beijing, China. Those who visited the Water Cube were treated to a blanket of color in the form of two vinca varieties from Goldsmith Seeds–’Cora Deep Lavender’ and ‘Cora White’–that thrived in the extreme tropical heat and high humidity.
Over three years, Beijing Flowers & Trees Corporation–the company responsible for the landscape during the Olympics–organized flower trials that included dozens of varieties from around the world. Cora, Sparkler and other Goldsmith varieties were among those that won out. ‘Sparkler Blush’ and ‘Sparkler White’ were planted in a bed outside the Bird’s Nest National Stadium.
Here are some growing tips for growing Cora vinca from bedding plant consultant David Koranski:
- Provide a well-aerated media: Finish plants in areas with protection from seasonal rains, and adequate dry back will occur in 18 to 24 hours.
- Maintain an EC range of 1.2 to 2.0 to finish plants: An EC less than 1.2 will stress plants and may cause susceptibility to disease. An EC greater than 2.0 in a dry substrate for longer than four to eight could result in iron-deficient plants with stunted roots and shoots.
- A slow release fertilizer can be added: Plants treated with slow-release fertilizers should not be allowed to dry down. Dry down could result in iron-deficient plants with stunted roots and shoots.
- Provide a pH no greater than 5.5: With a pH greater than 5.5, vinca may become susceptible to Thielaviopsis, creating and environment for secondary infections such as Phytophthora and Pythium.
- Monitor pH weekly: Vinca can raise the pH of the growing substrate by as much as one unit in 10 to 14 days. If Thielaviopsis is prevalent in your greenhouse, treat plants with a preventative fungicide during the first seven days after transplant.
- Grow vinca in soil temperatures no less than 70°F (21°C) day and night: An average daily temperature of 80°F (26.7°C) is optimum.
- Grow vinca in humidity of 40 to 70 percent: If growing in greenhouses, avoid foliage diseases such as Botrytis and Rhizopus with horizontal fans to lower humidity.
- Review and employ methods to eliminate Thielaviopsis: First, employ a pH of 5.5. Second, if this disease has infected your greenhouse, maintain an EC of less than 1.5. Third, use preventative fungicide following label directions.
- Use a reputable plant lab to diagnose problems so an effective treatment plan can be applied.
- Only use new plug trays and finish containers.
Other varieties displayed at the Olympics were PrimeTime petunias, Xtreme impatiens, La Bella snapdragons, Super Parfait dianthus, Antigua marigolds, Kiss gazanias, Asti osteospermums, Duchess torenias, Frost petunias, Ramblin trailing petunia, Magellan zinnias and Swizzle zinnias.