Water lobelia sessilifolia - Organic blue-purple - Hardy plantLong, strong spikes. It gives our garden an added extra. The water lobelia, swamp plant (Lobelia sessilifolia) is organically grown! It makes us so happy. The fast growing plant brightens up the pond's edge straight away. The blue purple flowers bloom in the summer. Put the plant in the sun or partial shade. Give it extra water during dry periods. The plant is grown organically. In other words, no chemical pesticides or fertilizers have been used to