TankBud

Lobelia cardinalis

Also known as Cardinal flower, Cardinal plant

FreshwaterStemSide shootsCuttings

Lobelia cardinalis (Lobelia cardinalis)
Aquarium Plants Factory · Used with permission

Care at a glance

Light
Medium light
CO2
CO₂ beneficial
Temperature
64–79°F
18–26°C
Max height
11.8 in
30 cm
Growth rate
Slow
Placement
Midground
Type
Stem
pH
6.0–7.5
Hardness
4–15 dGH
Spread
3.9 in (10 cm)
Nutrient uptake
Root + water column
Growth region
Submersed or emersed
Difficulty
Easy
Family
Campanulaceae
Origin
North America (eastern USA, Canada, Mexico, Central America)

Overview

Plant individual stems in the midground; it slowly forms tidy bushes rather than tall stems, which is why it is often used as a foreground-to-midground accent. It does fine in medium light without CO2 but stays more compact and a brighter fresh green with good light, CO2 and regular dosing. Growth is slow, so it needs little trimming. Propagate by cutting side shoots or topping a stem and replanting; trim the tops to keep it dense.

In the wild

Native to wet meadows, stream banks and marshy ground across North America, from the eastern United States and southern Canada down through Mexico into Central America. In the wild it grows emersed as a bog plant with tall spikes of bright red flowers, and the submersed aquarium form is the same species kept underwater.

Good to know

A member of the bellflower family Campanulaceae (subfamily Lobelioideae), not a true aquatic but a marsh plant that adapts to permanent submersion. The brilliant scarlet flowers are pollinated by hummingbirds in its native range. The compact 'Mini' cultivar widely sold for aquascaping is a dwarf selection that stays much shorter and bushier than the wild type.

Did you know

Did you know the submersed leaves look completely different from the emersed plant? Grown above water it makes broad pointed green-to-bronze leaves and red flower spikes, but underwater it produces narrower, fleshier light-green foliage, so a freshly converted plant can look like a different species for a few weeks.

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