Great Blue Lobelia
Perennial

Great Blue Lobelia

Lobelia siphilitica

Intense blue flower spikes that hummingbirds and bumblebees fight over in late summer. The bolder, taller cousin of cardinal flower.

Dangerous to cats

The ASPCA lists cardinal flower (Lobelia cardinalis) as toxic to cats and dogs: vomiting, diarrhoea, drooling, stomach pain, lethargy and heart rhythm disturbances, which is why a real ingestion is worth a vet call rather than a wait and see. Other lobelias are not listed by name, but they are the same genus, so give them the same caution.

Bloom Season
Aug - Sep
JFMAMJJASOND
Sun Requirements
◑ Part Shade2-4 hours
◐ Part Sun4-6 hours
Water Needs
High
Consistently moist
Size & Zones
2-3' tall
USDA Zones 4-9
Bloom Colors
Blue
Traits
♣ Native Species✿ Pollinator Friendly❖ Hummingbird Magnet△ Deer Resistant
Soil
LoamClay
Where to buy
Find Great Blue Lobelia plants on Amazon.
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Pairs Well With
Turtlehead
Perennial
Joe-Pye Weed
Perennial
Astilbe
Perennial
Iris
Perennial
Further Listening
Ep. 541: Coexistence and Maintaining Species Boundaries
In Defense of Plants
Uses the genus Lobelia to ask how closely related species stay distinct while growing side by side.
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Explore More
ColorBlue flowers
TypeAll perennials
TraitsNative SpeciesPollinator FriendlyHummingbird MagnetDeer Resistant
MonthsWhat blooms in AugWhat blooms in Sep
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