Source: Wikimedia Commons
Lobelia Cardinalis
IntermediateLobelia cardinalis
A stem plant with bright green underwater and red flowers above. Interesting difference between submersed and emersed forms.
About
Lobelia cardinalis is a perennial plant in the family Campanulaceae, native to North America, cultivated as a dimorphic aquatic plant in both submerged and emersed forms. The submerged leaves are beautiful bright light-green to yellow-green ovals, while the emersed form produces tall stems bearing deep crimson flowers. Some varieties develop purple-tinged undersides underwater, adding depth and contrast to aquascape layouts. Most commonly placed in mid to background positions, it forms dense bushy growth with regular trimming and height adjustment. Relatively easy to grow with CO2 addition and medium to strong lighting. Nutrient demands are moderately high, and periodic application of iron-containing liquid fertilizer enhances leaf color.
Size of the Lobelia Cardinalis
The Lobelia Cardinalis grows to 10-30cm.
Temperature & humidity for the Lobelia Cardinalis
The ideal temperature for the Lobelia Cardinalis is 18〜26℃.
Optimal water temperature is 18–26°C, and caution is needed in high-temperature conditions.
Basic Info
Origin
North America (eastern and central regions)
Lifespan
Perennial
Size
10-30cm
Temperature
18〜26℃
Watering & Fertilizer
Root tabs, CO2
Growing Tips
Lighting
Relatively easy to grow with medium to strong light. Adequate light keeps the leaves light green to yellow-green.
CO2 & Fertilizer
CO2 injection is assumed; on top of substrate fertilizer, regular liquid fertilizer containing iron brightens the leaf colour. Nutrient demand is fairly high.
Water Temperature & Quality
The optimal water temperature is 18–26°C. It dislikes high temperatures, so take care in tanks that heat up easily.
Trimming & Propagation
Trim while adjusting the height in the mid- to background to form a dense bush. Cut stems can be replanted to propagate.
Cautions
A dimorphic plant that grows both submersed and emersed. Switched to emersed culture, it produces deep red flowers on slender stems.
Lobelia Cardinalis FAQ
QWhat is the growing difficulty level for Lobelia Cardinalis?
Intermediate. A variety suitable for intermediate growers. Requires some cultivation experience and knowledge of environment management. Pay careful attention to temperature and humidity control.
QWhat is the ideal temperature for Lobelia Cardinalis?
The ideal temperature for Lobelia Cardinalis is 18〜26℃. Avoid sudden temperature changes and maintain a stable environment.
QHow large does Lobelia Cardinalis get?
The mature size of Lobelia Cardinalis is 10-30cm. This may vary slightly depending on cultivation environment and individual differences.
QHow should I water and fertilize Lobelia Cardinalis?
Lobelia Cardinalis: watering & fertilizer — Root tabs, CO2. Aim for appropriate frequency and amount.
QWhat is the typical price for Lobelia Cardinalis?
The price of Lobelia Cardinalis varies significantly by variety, characteristics, size, and lineage. Please check GrowerDirect's price guide for the latest market information.
Last updated: June 24, 2026
References & Sources
Edited & verified by: GrowerDirect Editorial Team
The classifications, regulations, and growing data on this page are created and verified based on the primary information database below.
Taxonomy & Authority
Regulations & Conservation Status
Sources: Ministry of the Environment Designated Invasive Species List (Invasive Species Act) / CITES Appendix II listed plant taxa (family and genus level)
Regulations may change. Always verify the latest information with the relevant authorities.
Related Species
Find listings for this species
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