Toxic Plant Known to be toxic - Toxic to mammals if ingested.
Image of Lobelia siphilitica
Source: Agnieszka Kwiecień

Plant Names

image of Flowering plant
Lobelia siphilitica
Great Blue Lobelia
Lobélie bleue

Synonyms

blue cardinal flower
great lobelia

Plant Characteristics

Bloom Colour: Blue Bloom Period: Jul - Sep
Max Height: 3.0 feet
Max Width: 1.5 feet (spreads by rhizome)
Light Condition:
Full sun More than 6 hours of direct sun a day
Part shade More than 2 or 3 hours but less than 6 hours of direct sun a day
Soil conditions:
Moisture medium Tolerates medium soil condition
Lifespan: Perennial plants that will come back year after year
Gardener Experience:
beginner friendly Suitable for beginner gardeners
does not spread Does not spread uncontrollably
plant spread by rhizome Spreads by rhizome
plant germinate easy Easy to germinate
plant self seeding Self-seeding
Landscape Uses:
wetland garden Suitable for wetland garden
rain garden Suitable for rain gardens
shoreline_rehab Suitable for shoreline rehabilitation
container suitable Suitable for container garden
school garden Suitable for school gardens
boulevard garden tolerant Tolerates boulevard garden conditions
Ecological Benefits:
Hummingbird friendly Supports hummingbirds
Bird friendly Supports birds
Pollinator garden Supports pollinators
Tolerates:
Deer Resistant Deer resistant
Rabbit Resistant Rabbit resistant
Limestone Tolerant Tolerates limestone conditions
Juglone Tolerant Tolerates juglone conditions
Transplantation Tolerant Tolerates transplantation
Special Features and Considerations:

Seed and plant distribution status

No seeds available for this plant.

We are not accepting seeds for this plant at the moment.

Plant Location

Native to Ottawa region: Yes

Distribution according to VASCAN

Distribution: Lobelia siphilitica
Ephemeral Native Introduced Excluded Extirpated Doubtful Absent

Thrives in Ecozones

  • Boreal Plains
  • Mixed Wood Plains

Ecological Benefits

Butterflies Supported by Lobelia siphilitica

Specialized Bees Supported by Lobelia siphilitica

No bee data available for this plant.

Complementary Plants

Substitute For Non-Native Plants

  • Buddleia (Butterfly Bush)
  • Delphinium (Delphinium)
  • Iris pseudacorus (Yellow Iris)
  • Iris (Iris Cultivars)
  • Hesperis matronalis (Dame Rocket)

Sowing Information

Download Seed Envelope Labels (PDF)
  • Sowing depth: Surface sow
  • Sow by February
  • Stratification duration: 60 days
  • Self-seeding

Harvesting and Seed Sharing

  • Harvest start month: October
  • Harvesting indicator:
    • Pods are brown, seeds are dark, and crisp, and little stem connecting the pod to the main stem is brown (not green)
  • Harvesting:
    • Cut stem (including pods), let air dry in paper bag, then shake seeds off after a few days
  • Seed viability test:
    • No test needed before donating
  • Packaging measure: Half of one, 1/32 teaspoon
  • Seed storage:
    • Air dry in paper bag or open container, for a few days until crisp
    • Shake seeds to move them once in a while to prevent molding
  • Cultivar: Yes, do not donate unless you know source, and there are no known cultivars in your garden or at proximity
  • Remove non-seed material
  • Harvesting video: Watch here

Toxicity Notes

Toxic to mammals if ingested.