Cardinal flower
Lobelia cardinalis · Campanulaceae
The gardener's calendar
Ideal time to plant cardinal flower: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Deciduous
- Flowering
- July to September
- Adult size
- 60 to 90 cm in height
- Growth
- Moderate
- Hardiness
- Down to -15°C
- Origin
- North America
- Soil type
- Moist, rich in organic matter
Care
Watering
Scarlet lobelia loves consistently moist soil: water regularly, especially during the growing season and in hot spells. Avoid waterlogging that could rot the roots. In autumn, gradually reduce watering to prepare the plant for winter dormancy.
Light exposure
Plant in partial shade to sunny locations depending on your climate. In warm regions, a semi-shaded spot will protect the plant from summer sunburn. In temperate climates, morning sun exposure is ideal for abundant flowering.
Pruning and maintenance
Remove spent flowers regularly to extend the flowering period. In late autumn, cut back dry stems to ground level. In spring, clear away dead debris to encourage new growth.
Soil and planting
Prepare soil enriched with compost or blonde peat to ensure good moisture retention. This plant is perfect for pond borders, marshy areas, or moist beds. Space plants 40 to 50 cm apart.
Fertilizer
Apply a balanced fertilizer in spring and an additional feed in early summer to support flowering. A mulch of organic matter at the base will help maintain moisture and gradually enrich the soil.
Pests and diseases
Scarlet lobelia is generally robust. Watch out for slugs and snails, particularly in very moist soils. Good drainage and proper foliage aeration will minimize the risk of rot or fungal diseases.
Did you know?
Scarlet lobelia takes its scientific name 'cardinalis' from the striking red color of its flowers, which recalls the robes of Catholic cardinals. This plant was widely used by Eastern Native Americans for its traditional medicinal properties, and it remains a major attraction for hummingbirds in North America, which pollinate it enthusiastically in the heart of summer.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Peach-leaved bellflowerCampanula persicifolia
- Clustered bellflowerCampanula glomerata
- Trailing bellflowerCampanula poscharskyana
- Dalmatian bellflowerCampanula portenschlagiana
- PānakenakeLobelia angulata
- Carpathian bellflowerCampanula carpatica
Tips generated and checked by Viridia — adapt them to your local climate.