Image for Blue Lobelia

Blue Lobelia

Scientific name

Lobelia siphilitica


Blue Lobelia is a wildflower species that can grow up to 1 m in height. This plant may also be known by the common name Blue Cardinal Flower. The leaves are light green coloured, alternately arranged, ovate shaped, and have finely toothed margins. The flowers are attractive and showy, light to dark blue in colour with white patches, have two lips, with the upper lip having two lobes that curl backward and the lower lip having three lance shaped lobes that point downward, appear in dense clusters on tall racemes, and bloom between July and September. The flowers are beneficial to pollinator species, like bees and butterflies. The seeds are also beneficial to wildlife species, like birds and small mammals.

Planting conditions

Blue Lobelia grows best in moist to wet conditions with full to partial sun exposure. It prefers organically rich, poorly drained humus, sand, clay, or loam soil types. It is tolerant to deer grazing, periodically flooded areas, and shade. It is intolerant of drought and dry conditions. This wildflower can be naturally found in wet meadows, wet forests, around marshes or swamps, and along river or lake shorelines.


  • Plant height:
    • Max 1.5m
    • Max 2m
    • Max 3m
    • Any
  • Moisture level:
    • Moist
    • Wet
    • Flood Tolerant
  • Light conditions:
    • Full sun
    • Partial sun
  • Soil type:
    • Sandy
    • Loamy
    • Clay
    • Humus
  • pH:
    • Normal
  • Depth:
    • Wildflower
  • Eco Zone:
    • 2b
    • 3a
    • 3b
    • 4a
    • 4b
    • 5a
    • 5b
  • Plant type:
    • Wildflower
  • Height:
    • 1 m
  • Spread:
    • 0.5m