Lobelia siphilitica
A very easy lobelia usually lower than indicated height, self-seeding through borders to create informal colonies. Sturdy blue flower spikes bloom from midsummer until early fall. Less demanding about site characteristics than cardinal flower.
Thrives in sun or part shade with average moisture. The self-seeding habit establishes naturalistic drifts. Native to eastern North America. The blue candles provide excellent vertical interest. More adaptable and easier than many lobelias. White-flowered form available but must be selected when blooming.
Growing Conditions
Light: full sun to part shade
Moisture: average
Soil: average moisture-retentive
Hardiness zone: 4
Maintenance: low
Size & Habit
Height (cm): 90
Spread (cm): 30
Habit: upright clump
Seasonal Interest
Flowering period: July–Aug
Seasonal interest: midsummer to fall bloom; blue spikes; self-seeding colonies
Foliage: green
Flower: blue
Ecology & Notes
Wildlife value: pollinators
Deer/Rabbit resistance: yes
Habitat: borders; naturalistic plantings; native gardens; moist sites
Features: sturdy blue spikes; self-seeding; informal colonies; easy culture; less fussy than cardinalis; native
Notes: very easy; self-seeds to form colonies; native to E North America; less picky than cardinalis