Lobelia Flower Trailing Lobelia Lobelia Blue Moon How to Plant, Grow, and Care for Lobelia 21 Blue Flowers Garden Ideas To Make Your Garden Look Like a Dream. Lobelia cardinalis grows wild in Northern America. In the nursery this plant is cultivated in marshy conditions, forming dark green leaves which are purple underneath. In aquariums the leaves turn a beautiful shade of light green, with stems 10 30 cm tall and 5 10 cm wide. It needs intensive light to thrive. Widely used in Dutch aquariums in so called "plant streets''. In open aquariums it grows above the water surface, where it forms very beautiful scarlet flowers and the leaves regain their colour. Can be used in garden ponds. Product Details: Type: Stem Growth: Medium Light: Low Origin: North America Height: 20 30+ CO2: Medium