The best spot to plant your Riviera Lobelia is a spot which soaks up the sun in the morning, followed by filtered or shaded afternoons. These cool season thrivers prefer average to moist soil but will not tolerate standing water. Not heavy feeders, a pre-applied granular, slow-release with a once per week dose of a complete balanced liquid feed should do the trick. Trim off any faded blooms to encourage new growth and flowering. During hot periods lobelia may die back, but when the temperatures cool back down the plant should bounce back.