What's New with Lisianthus?
Select a cut flower bed with a pH of 6.8-7.2, high in organic matter with good drainage. Work the bed to a depth of 12 inches to promote deep rooting. Transplant seedlings on time (prior to root wrap) for optimum establishment. Set the seedling “slightly high” in the bed to prevent stem rot (rhizoctonia). A spacing of 4 x 6 inches/10 x 15 cm works well and allows for sufficient air movement. Some growers set plants tighter and then leave the center row(s) empty. Following transplanting, apply water overhead for a few weeks or until the roots penetrate into the outer soil. Once established apply water via drip irrigation to keep the foliage dry. In areas of low humidity, some growers bury the irrigation lines 3-4 inches below the soil surface, which keeps the surface dry (minimizes botrytis) and promotes deeper root penetration.Fertilize as needed to maintain an EC of 1.2-1.4 mmhos (2:1 dilution). Prior to visible bud, water and fertilize regularly. Then, tone the plants as they mature and flower buds appear by increasing the time between irrigations. Lisianthus develops and flowers based on a combination of temperature, light, and photoperiod. A minimum soil temperature of 55F/13C is necessary for active growth. Once plants are established, higher temperatures, stronger light intensity, and longer photoperiods accelerate development.
For this reason lisianthus is into three groups based on their response to the above factors, similar to forcing snapdragons. The use of high intensity lights and temperature manipulation allows growers to economically force lisianthus year-round in cooler, high latitude areas during the winter months. In general, plants begin to flower 16 weeks following transplant under natural conditions. For the best quality cut flowers reduce the temperature (< 75F/24C) and light intensity to 1,500-2,000 foot candles/16,000-22,000 lux. Ultraviolet light intensifies the flower color. Cut stems when one or two flowers are open and place in tepid (68F/20C) water and store at 39F/4C. A flower preservative is strongly recommended and increases vase life by 40-50%. Consumers are attracted to lisianthus because of the wide color range, unique flower forms, and long vase life. An American native offering a simple beauty with great sophistication.
The above information is intended only as a guide and is based on general growing practices.
Results may vary based on climate and local conditions.
Bob Croft is a 22-year veteran of Sakata Seed America, working in technical support and trials.
Bob supports growers with culture information and feedback on trials. Contact him at [email protected]