About
Lobelia cardinalis, the cardinal flower, is an erect, clump-forming herbaceous perennial to 90 cm with rather glossy, lime-green, oblong leaves and brilliant scarlet, two-lipped flowers 5 cm long in terminal spikes. One of the most intensely red-flowered of all hardy perennials, outstanding in a moist, sheltered border or at the waterside.
About the genus
Lobelia are annuals, perennials or shrubs with simple leaves and showy, two-lipped flowers that may be solitary or borne in racemes or panicles. A versatile and widely grown genus for borders, containers, bog gardens and wildlife gardens.
Growing conditions
SunlightFull sun, Partial shade
Soil typeLoam
Soil pHAcid, Alkaline, Neutral
Soil moisturePoorly-drained
AspectSouth-facing, West-facing, East-facing
ExposureExposed, Sheltered
UK hardinessH3
Plant details
Plant typeBogs, Herbaceous Perennial
HabitClump forming
FoliageDeciduous
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCottage and informal garden
Native toN America
ToxicityHarmful if eaten, skin irritant. Wear gloves and other protective equipment when handling Wear gloves and other protective equipment when handling. Pets: Harmful if eaten, skin irritant. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Care notes
CultivationGrow in deep, fertile, reliably moist soil in full sun or partial shade
PruningCut back after flowering
PropagationPropagate by seed sown in gentle heat as soon as ripe, or by bud cuttings in late summer
Pest resistanceMay be susceptible to slugs
Disease resistanceMay be susceptible to crown rot