Bacopa caroliniana
Bacopa caroliniana
Also known asLemon bacopa · Blue waterhyssop · Colorata bacopa
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 and Cuba, from Virginia and the Carolinas west to Texas, in marshes, pond margins, slow streams and wet meadows. It is one of the few aquarium stem plants native to North America, a semiaquatic subshrub of the family Plantaginaceae. It grows both emersed, with rounder, waxier, succulent leaves, and submersed, with more oval leaves about 1–2 cm long in opposite pairs along a thick upright stem. Crushed leaves give off a distinct lemon-to-lime scent, the source of the common name lemon bacopa, and the plant bears small five-petalled blue flowers. Submersed leaves are medium to bright green, and under strong light the tips and upper stem flush copper, bronze, pink or purple.
Outdoor pond use
- USDA zones
- 5–11 (winter low around -29°C or warmer)
Care notes
One of the easiest stem plants for beginners, growing in low to high light, with or without CO2, in soft or hard water. Under low light it grows slowly but stays healthy and green, leaning toward the surface; under bright light with CO2 it grows faster, stays compact and bushy, and the tips colour up copper to bronze. The thick stems and paired leaves give it a tidy, structured look next to more flowing stem plants. Plant in groups of five to eight, pushing each stem in with two or three nodes buried; the buried nodes root within days. Trim by cutting the top 10–15 cm and replanting the cuttings, and the lower stems throw side shoots. It feeds from both roots and the water column, so root tabs help but are not essential, though note that the copper in many liquid fertilisers is hazardous to shrimp. It tolerates a wide pH and is reasonably cold-hardy, handling roughly 15°C to 28°C, which suits unheated or cool tanks. Propagation by cuttings is quick and reliable, making it a fine first stem plant. It also grows emersed in terrariums, paludariums and warm-climate bog gardens, where it flowers blue. Moving between emersed and submersed growth brings a short adjustment where old leaves shed before new, condition-matched leaves appear. It is an ornamental stem plant, not a crop, so it is not grown in media-bed aquaponics or hydroponics.