Bacopa caroliniana
Bacopa caroliniana
Also known asLemon bacopa · Giant bacopa · Blue water hyssop
Water parameters
Light and nutrients
Substrate type: inert ok. Propagation: stem cuttings.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
| Dirted tank (mineralized topsoil) (DIY soil substrate) | slightly acidic | very high |
With fish
Origin and habitat
Native to the southeastern United States, from Texas and Florida north through the Carolinas. Found in marshes, pond margins, slow streams, and wet meadows. The species grows both emersed (above water, with round, succulent leaves) and submerged (with more elongated, thinner leaves). Bacopa caroliniana is one of the few aquarium stem plants native to North America. The leaves are arranged in opposite pairs along a thick, upright stem. Submerged leaves are oval, 1–2 cm long, and medium to bright green. Under strong light, the leaf tips and upper portions develop a copper to bronze tint. The plant has a subtle lemony scent when the leaves are crushed, which is noticeable when handling it during trimming.
Outdoor pond use
- USDA zones
- 5–11 (winter low around -29°C or warmer)
Care notes
One of the easiest stem plants for beginners. Grows in low to high light, with or without CO2, in soft or hard water. Under low light, growth is slow but healthy; stems stay compact and green. Under high light with CO2, growth accelerates and the tips develop copper to bronze coloring. The thick stems and opposite leaf arrangement give it a structured, orderly appearance compared to more flowing stem plants. Plant stems in groups of 5-8, pushed into the substrate with 2-3 nodes buried. The buried nodes produce roots within days. Trim when stems reach the surface by cutting the top 10–15 cm and replanting the cuttings. The cut lower stems produce side shoots. Growth is moderate; weekly or biweekly trimming keeps a group tidy. Nutrient requirements are moderate. Root tabs help but aren't strictly necessary because Bacopa feeds from both roots and the water column. Not demanding about water chemistry; it grows well in pH 6.0-8.0 and soft to hard water. Propagation by cuttings is reliable and fast. One of the best plants for a first planted tank because it's almost impossible to kill and provides a good learning experience for stem plant management. The plant can also be grown emersed in terrariums, paludariums, and outdoor bog gardens in warm climates. The emersed form has rounder, thicker leaves and can flower with small blue to purple blooms. Transitions between emersed and submerged growth involve a brief adjustment period where old leaves may shed before new growth adapted to the current conditions emerges.