Two new colors to the Magadi lobelia series for 2009 are Ocean Blue and Basket Purple + Eye. Ten total varieties make up this series of heat-loving lobelia.
Use one plant per 4- to 5-inch pots, and four to five plants for 12-inch baskets. Crop time for 5-inch pots starting from a rooted cutting is about six to eight weeks. Use a well-drained, peat moss–based substrate (add perlite for better drainage) with low salt levels and a pH around 5.8-6.2.
Start with a constant feeding program after roots have developed. Use 200- to 250-ppm nitrogen and a well-balanced fertilizer. Cool temperatures encourage branching, compact growth and flowering. Start warm; after roots have developed, the optimum temperature ranges are 70-75° F days and 55-60° F nights.
Grow on the dry side; avoid wet feet, stagnant water and overhead watering. These varieties prefer high light levels: 5,000-9,000 foot-candles.