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Lobelia siphilitica (Blue cardinal flower)
1 hour care
per year
per year
0.7m
Max height
Max height
0.4m
Max spread
Max spread
2-5 years
To maturity
To maturity
Low
Toxicity
Toxicity
Plant details
Botanical name
Lobelia siphilitica
Other names
Blue cardinal flower, Great lobelia , Tall blue lobelia, Virginia bellflower, Vomit root
Genus
Lobelia Lobelia
Species
L. siphilitica - L. siphilitica is an upright, clump-forming, herbaceous perennial with erect stems bearing ovate to broadly lance-shaped, toothed, softly hairy, light green leaves and dense racemes of tubular, two-lipped, blue flowers from late summer to mid-autumn.
Lobelia siphilitica is: Deciduous
Habit
Clump-forming, Upright
Toxicity
Severe discomfort may result if ingested
Flower
Blue in Summer; Blue in Autumn
Foliage
Light green in Spring; Light green in Summer; Light green in Autumn
How to care
Watch out for
Specific pests
Slugs Slugs
Diseases
May be prone to a virus
Crown rot Crown rot
General care
Pruning
Cut back after flowering.
Propagation
Seed cam be sown as early as late winter.
Propagation methods
Division, Seed
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Where to grow
Lobelia siphilitica (Blue cardinal flower) will reach a height of 0.7m and a spread of 0.4m after 2-5 years.
Suggested uses
Beds and borders, City, Coastal, Cottage/Informal
Cultivation
Plant in deep, fertile, reliably moist soil in sun or partial shade. Best in partial shade except in cool, northern climates. May self-seed in optimum growing conditions.
Soil type
Chalky, Clay, Loamy, Sandy (will tolerate most soil types)
Soil drainage
Moist but well-drained, Moisture-retentive
Soil pH
Acid, Alkaline, Neutral
Light
Partial Shade, Full Sun
Aspect
South, East, West
Exposure
Exposed, Sheltered
UK hardiness Note: We are working to update our ratings. Thanks for your patience.
Hardy (H4)
Companion plants
We do not currently have companion plants added for this plant.
Botanical name
Lobelia siphilitica
Other names
Blue cardinal flower, Great lobelia , Tall blue lobelia, Virginia bellflower, Vomit root
Genus
Lobelia Lobelia
Species
L. siphilitica - L. siphilitica is an upright, clump-forming, herbaceous perennial with erect stems bearing ovate to broadly lance-shaped, toothed, softly hairy, light green leaves and dense racemes of tubular, two-lipped, blue flowers from late summer to mid-autumn.
Foliage
Deciduous
Habit
Clump-forming, Upright
Toxicity
Severe discomfort may result if ingested
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Colour
Flower
Blue in Summer; Blue in Autumn
Foliage
Light green in Spring; Light green in Summer; Light green in Autumn
How to care
Watch out for
Specific pests
Diseases
May be prone to a virus
Specific diseases
General care
Pruning
Cut back after flowering.
Propagation
Seed cam be sown as early as late winter.
Propagation methods
Division, Seed
Monthly care advice
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Where to grow
Lobelia siphilitica (Blue cardinal flower) will reach a height of 0.7m and a spread of 0.4m after 2-5 years.
Suggested uses
Beds and borders, City, Coastal, Cottage/Informal
Cultivation
Plant in deep, fertile, reliably moist soil in sun or partial shade. Best in partial shade except in cool, northern climates. May self-seed in optimum growing conditions.
Soil type
Chalky, Clay, Loamy, Sandy (will tolerate most soil types)
Soil drainage
Moist but well-drained, Moisture-retentive
Soil pH
Acid, Alkaline, Neutral
Light
Partial Shade, Full Sun
Aspect
South, East, West
Exposure
Exposed, Sheltered
UK hardiness Note: We are working to update our ratings. Thanks for your patience.
Hardy (H4)
USDA zones
Zone 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4
In order to add a note on this plant, please add this plant to your plant lists.
| This plant likes... | Garden match | |
| Soil types: | Chalky, Clay, Loamy, Sandy (will tolerate most soil types) | Tell us... |
| Soil drainage: | Moist but well-drained, Moisture-retentive | Tell us... |
| Soil pH: | Acid, Alkaline, Neutral | Tell us... |
| Light: | Partial Shade, Full Sun | Tell us... |
| Aspect: | South, East, West | Tell us... |
| Exposure: | Exposed, Sheltered | Tell us... |
| Hardiness: | Hardy (H4) | Tell us... |
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