Purple Bacopa (Bacopa caroliniana 'Purple') is a colour-selected cultivar of Lemon Bacopa with small, rounded, opposite leaves that develop rich purple to violet colouration across the upper leaf surface and stem under high light conditions — the most distinctly coloured Bacopa available and the only stem plant in the catalog that produces genuine purple tones without CO₂ injection. Under lower light the leaves remain green with purple tinting at the margins; under medium to high light with consistent iron the upper leaf surfaces flush deep purple-violet and the stems take on a reddish-purple hue that makes the plant read clearly as a colour event in the layout. The growth form is naturally compact and slightly bushy compared to faster-growing stem plants — Bacopa does not shoot upward as aggressively as Hygrophila or Pennywort and produces side branches more readily, giving a well-established group a fuller, more rounded appearance with less trimming required. Lightly aromatic when trimmed above the waterline. Fully safe with all Neocaridina, Caridina, and snails.
Not RequiredCO₂
64–82°FTemperature
Med–HighLighting
What to Expect
Colour, Growth & Behaviour
Rich purple-violet colouration develops under medium to high light — under low light leaves are predominantly green with purple tinting on new growth and at margins. Under medium to high light the colour intensifies progressively — new leaves emerge with deeper purple tone and older leaves retain more purple than they would under lower light. The full expression of the cultivar requires consistent high light over several weeks; plants transferred from low to high light conditions develop their full colour over two to four weeks as new growth responds to the increased intensity.
Iron supplementation deepens and sustains the purple — consistent liquid iron in the fertiliser routine is the second most important variable for purple intensity after light. Plants with adequate iron and high light produce the deepest, most saturated purple across the broadest area of leaf surface. Without iron, the colouration is present but paler and more confined to leaf margins and new growth tips rather than across the full leaf face.
Small, rounded, opposite leaves on compact stems — the leaf form is characteristic of Bacopa — small, broadly oval to rounded, carried in opposite pairs along the stem at regular intervals, with a slightly succulent, firm texture that holds its shape when handled above water. The compact leaf size and moderate inter-node spacing give each stem a neat, regular appearance that suits aquascape-style layouts where plant form is part of the design intention.
Slower, more compact growth than most background stem plants — Purple Bacopa grows more slowly than Willow Hygro, Pennywort, or fast stem plants — adding new internodes at a measured pace and branching readily rather than shooting straight upward. This means less frequent trimming than fast-growing background plants, and a natural tendency toward a bushy, multi-stemmed form rather than long single stems. In most tanks a trimming cycle of six to eight weeks is sufficient.
Differentiates from Lemon Bacopa on colour, not form or care — Purple Bacopa and Lemon Bacopa are the same species and share identical growth form, care requirements, and parameter tolerances. The difference is purely the leaf colouration under high light — Purple flushes violet-purple; Lemon produces yellow-green tones. In a layout using both, the two plants provide the clearest colour contrast achievable between two plants with identical care needs.
How to Set It Up
Getting Started
1Plant in groups of five or more stems in the midground or background — strip the lowest 3cm of leaves and plant at 2–3cm spacing in a group. A group of five or more stems planted together produces a visually coherent colour mass from the outset — individual stems of Bacopa planted widely apart read as isolated plants rather than a colour event. Position in the midground where the purple colouration is visible against the green backdrop of taller background plants.
2Use medium to high light — colour develops over two to four weeks — if upgrading from low to high light after initial planting, expect two to four weeks before the full purple expression develops on new growth under the improved conditions. Do not evaluate colour performance during this transition period — the plant needs time to grow new leaves in the higher light environment.
3Dose liquid iron consistently from the start — add a comprehensive liquid fertiliser with iron to the regular dosing schedule from the day of planting. Iron is a prerequisite for the deepest purple expression alongside high light — plants in iron-deficient water remain green even under high light, so both conditions must be met simultaneously.
4Trim when stems reach desired height and replant tops — when stems reach the surface or exceed the desired height, cut the top 8–10cm, strip the lowest leaves, and replant in front of or alongside the original stem. The original stem branches from the cut node. Bacopa is slightly slower to recover from trimming than faster-growing stem plants — allow two to three weeks after trimming before the full colour expression returns on new growth.
💡 Bonus Tip
Purple Bacopa and Lemon Bacopa planted in adjacent groups in the same midground zone — Purple on one side, Lemon on the other, with a piece of driftwood between them — creates the most distinct warm-cool stem plant colour contrast achievable without CO₂ in the catalog. The deep violet-purple of the Purple cultivar against the warm yellow-green of Lemon reads as a composed, complementary pairing rather than an accident of planting, and both plants grow at the same rate and require the same trim cycle, making maintenance of the two groups completely synchronised.
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Browse more aquatic plantsPair Purple Bacopa with Lemon Bacopa, Willow Hygro, or Anubias for a complete planted midground. Browse our Aquatic Plants collection.
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