About
In late summer it produces tubular blue flowers in closely arranged spikes on tall flower stems. A marginal aquatic perennial, to 1.2m tall, forming a clump of lance-shaped leaves borne on long, upright stalks. A good plant to provide a strong, vertical accent at a pond margin.
About the genus
Pontederia are herbaceous perennials from marginal aquatic habitats, forming clumps of erect, linear or lance-shaped leaves, with 2-lipped blue flowers in dense terminal spikes in late summer and early autumn
Growing conditions
SunlightFull sun
Soil typeLoam
Soil pHAcid, Alkaline, Neutral
Soil moisturePoorly-drained
AspectSouth-facing, West-facing
ExposureSheltered
UK hardinessH5
Plant details
Plant typeAquatic, Bogs
HabitColumnar upright, Clump forming
FoliageDeciduous
Height1-1.5 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesArchitectural, Patio and container plants
Native toE. and S. USA, Mexico
Care notes
CultivationGrow in aquatic planting baskets of fertile, loamy soil at the margins of a pool or in a large, water-filled tub on a sheltered patio; submerge in no more than 20cm of water. Site in full sun. See pond plants and bog gardens for further advice
PruningCut back leaf stems to just above the water level in early winter
PropagationPropagate by seed, sown in containers outdoors as soon as ripe. Divide in late spring
Pest resistanceGenerally pest-free
Disease resistanceGenerally disease-free