Photo: no rights reservedCC0 1.0via iNaturalist
Cardinal Flower Plant Care
Lobelia cardinalis L.
Updated · Sources · How we source care data
Lobelia cardinalis, the cardinal flower, is a species of flowering plant in the bellflower family Campanulaceae native to the Americas, from southeastern Canada south through the eastern and southwestern United States, Mexico and Central America to northern Colombia.
Every 3–7 days
Full sun to part shade
50–75°F
40–70%
At a glance
How do you care for Cardinal Flower?
Water Cardinal Flower every 3–7 days, letting the top layer of soil dry out between waterings, and give it full sun to part shade. It prefers temperatures of 50–75°F (10–24°C) and 40–70% humidity. Fertilize it every 6 months during the growing season. The ASPCA lists it as toxic to cats and dogs, so keep it out of reach of pets.
Where Is the Cardinal Flower Native To?
What Is the Cardinal Flower?
Cardinal Flower (Lobelia cardinalis) belongs to the Campanulaceae family within the Lobelia genus. Cardinal Flower is native to the Americas, from southeastern Canada south through the eastern and southwestern United States, Mexico and Central America to northern Colombia. Cardinal Flower is also known as Indian Paintbrush, Great Lobelia, Scarlet Lobelia.
Cardinal Flower displays a spreading, low-growing perennial growth habit, reaching up to 0.5 ft tall with a spread of approximately 1.5 ft. Cardinal Flower produces tubular flowers in shades of blue, purple, pink, or white.
Leaf size: approximately 2 inches.
How Often Should You Water a Cardinal Flower?
Lobelia cardinalis requires watering every 3–7 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 3–7 days
Let soil partially dry between waterings
What Light Does the Cardinal Flower Need?
Cardinal Flower thrives in full sun to part shade.
Light Requirement
Full sun to part shade
What Temperature and Humidity Does the Cardinal Flower Prefer?
Lobelia cardinalis grows best at temperatures of 50–75°F. Cardinal Flower prefers humidity levels of 40–70%.
Temperature
50–75°F
Humidity
40–70%
What Soil Mix Works Best for a Cardinal Flower?
Moist, well-draining soil rich in organic matter. Good drainage is essential for Cardinal Flower to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Cardinal Flower?
Feed Cardinal Flower every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Cardinal Flower?
Repot every 1-2 years in spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Cardinal Flower?
Cardinal Flower can be propagated through seeds, division. Similar propagation techniques also apply to edging lobelia plant care, which shares the same genus.
Is the Cardinal Flower Toxic to Pets and Children?
Toxic to cats and dogs
Source: ASPCA Animal Poison Control Center plant list. View the ASPCA entry
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Cardinal Flower?
Cardinal Flower is susceptible to aphids, slugs, snails. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Cardinal Flower Need?
Cardinal Flower grows outdoors in USDA Zone 3b – 11b. It survives winters down to planting zone 3b. Cardinal Flower is native to the Americas, from southeastern Canada south through the eastern and southwestern United States, Mexico and Central America to northern Colombia.
Hardiness Zone
Zone 3b – 11b
Keep exploring plants
Cardinal Flower is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Lobelia genus — compare its care with other Lobelia species on PlantoScan.
Lobelia is part of the Campanulaceae plant family — browse all Campanulaceae genera and species.
Cardinal Flower thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Lobelia cardinalis L., family Campanulaceae (first published in Sp. Pl. : 930 (1753)) — World Flora Online record, IPNI name record, Wikidata.
- Pet toxicity: The ASPCA lists Cardinal Flower as toxic to cats and dogs. Source: ASPCA Toxic and Non-Toxic Plant List.
- Photo: Public domain, CC0 1.0, iNaturalist — original.
- Hardiness zone: USDA Zone 3b – 11b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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