In lobelia, the goal of everyone’s breeding programs is heat tolerance, and the search for a longer-performing lobelia continues. Each year, there are new breakthroughs; ‘Lucia Dark Blue’, like the Laguna series, is heat tolerant, easy-to-grow and has beautiful, deep cobalt-blue flowers. Bred in tropical Japan and trialed in California, Michigan, New Hampshire and Florida, the goal of this new lobelia series from Proven Winners is to keep updating the portfolio with the newest and best breeding for season extension.
Lobelia has undergone a revolution of sorts since “the old days,” 20 years ago, when almost all of them were grown from seed and were mostly Lobelia erinus types. They were valued for their incredible blue and violet jewel tones, but known for their spring performance and summer failure, except in areas of the country with very mild summers. Night temperatures above 55° F used to spell the end of the lobelia season for most of us. New breeding with different species and forms of lobelia has brought us to today, where heat tolerance has been radically improved, and the size and shape of plants offer a lot more options. The old seed lines are still available, but vegetative breeding has brought this plant a long way in improving the season and range of its performance.
Lucia can be scheduled using all the same guidelines growers have for the Laguna series. Spring is the primary season, but a lot of growers are also doing fall crops to get these great blues into fall displays at retail. A 4- to 5-inch container (one liner per pot) will need four to six weeks to finish; 6-inch and gallon containers (one liner per pot) require five to seven weeks; an 8-inch (three liners per pot) container needs seven to nine weeks; and a 10- to 12-inch container (three to five liners per pot) will take 10 to 12 weeks.
The old seed forms had a lot of rooting issues and were susceptible to root rots. While most of those issues have been improved, it is still a good idea to use a well-drained media and keep an eye on watering, especially right after transplanting. Make sure plants have good high-light levels and air circulation. They are high-light-preference plants, so low-light production areas will reduce vigor and overall quality.
Constant application of a balanced feed at a rate of 200- to 250-ppm nitrogen that supplies 25 to 30 percent ammoniacal nitrogen will promote fast growth and lush green color. Reduce ammonium levels if you begin to see signs of stretch. Aim for a pH of 5.5-5.8 at all times and an EC of 0.6-0.9 (using a 2:1 extraction method).
To establish a good root system, grow plants moderately warm at 68-70° F during the day and 65-68° F at night. Once the plants are rooted and begin filling the container, drop to a constant temperature of 63-65° F to slow the growth and harden off the plant. High light levels are needed to promote compactness and accelerate the natural branching of this plant. Once established, ‘Lucia Dark Blue’ does well when hardened off outdoors in the spring months, but avoid temperatures below frost level, especially until plants are hardened off.
For pots 6 inches and smaller, pinch at transplant only if needed. For hanging baskets and pots larger than 6 inches, soft pinch at planting and trim around the pot just prior to hanging. Regarding growth regulators, they are usually not necessary, but if for some reason you are forced to keep plants at lower than optimal light levels try sprays of 5- to 10-ppm Sumagic (uniconazole) to control stretch.
As we find new advances in lobelia performance and add them to the Lucia series, we will always be looking for the plants that give the consumer the best performance over the longest season. Expect changes in the lineup, as new breeding is rapidly advancing the performance of lobelia. You’ll want to stay on the cutting edge.
Proven Winners maintains cultural information on all Proven Winners, Proven Selections and Proven Winners ColorChoice varieties online. For complete cultural information about Lucia Dark Blue lobelia, visit www.pwcertified.com/grower/plants/culture.cfm .