Red Ludwigia (Ludwigia sp. 'Red') is the most colour-accessible red stem plant in the catalog — a fast-growing, broadly tolerant species that produces genuine red to deep orange-red colouration on the upper leaf surfaces under medium to high light, without CO₂ injection, in parameter ranges compatible with Neocaridina keeping. Most red stem plants require CO₂ and high light to produce their defining colour; Red Ludwigia produces meaningful red colouration under medium light in a standard low-tech setup and responds to CO₂ and higher light with intensified, deeper colour rather than requiring them as prerequisites. The leaves are broad and oval, carried in opposite pairs along upright stems, with the upper surface producing the red-orange colouration and the underside remaining a contrasting green or pinkish-green — a two-toned leaf quality visible when the leaves are viewed at an angle. Iron availability is the primary chemical driver of colour intensity alongside light. Fast-growing and easy to trim and propagate. Fully safe with all Neocaridina, Caridina, and snails.
EnhancesCO₂
64–84°FTemperature
Med–HighLighting
What to Expect
Colour, Growth & Behaviour
Red to deep orange-red on upper leaf surfaces under medium to high light — the colouration develops on the upper surface of each leaf — the side facing the light source — while the underside remains green to pinkish-green. Under medium light the colour sits in the orange-red range; under high light with iron the upper surfaces develop deeper, more saturated red. New growth at the stem tips is always the most intensely coloured part of the plant — older leaves below the growing tip gradually become more green as they age and are shaded by newer leaves above them.
Iron is the primary chemical driver of colour intensity — consistent liquid iron in the fertiliser routine produces noticeably deeper, more saturated red at equivalent light levels compared to plants in iron-deficient water. This is the most impactful single adjustable variable for colour after light intensity — if Red Ludwigia is green or orange rather than red in a tank with adequate light, iron deficiency is the most likely cause. Dose comprehensive liquid fertiliser with iron two to three times weekly and evaluate colour on new growth over two to three weeks.
CO₂ enhances colour depth and growth rate significantly — without CO₂ Red Ludwigia grows at a moderate pace and produces meaningful red colouration under medium to high light. With CO₂ at 20–30ppm the growth rate increases substantially and the red colouration is deeper and develops faster on new growth. CO₂ is not required for the plant to be red — it is required for it to be maximally red and growing at maximum rate.
Fast growing — regular trimming required — under good conditions Red Ludwigia grows quickly and reaches the surface within weeks of planting. Establish a regular trimming rhythm — cut stems at the desired height, strip the lowest 3cm of leaves from cut tops, and replant immediately. The original stem branches from the cut node. Trimmed and replanted regularly, a group of Red Ludwigia becomes progressively denser and more colourful at each cycle.
Broad opposite leaves with two-toned red-upper, green-lower surfaces — the leaf form is distinctive among red stem plants — broad, oval, clearly two-toned upper-to-lower when viewed at an angle. The visual contrast between the red upper surface and green-pink underside adds depth to the plant's appearance when stems are viewed from the side, and makes individual leaves more visually interesting than the uniformly coloured leaves of some other red stem species.
How to Set It Up
Getting Started
1Plant in groups of five to seven stems in the background — strip the lowest 3cm of leaves from each stem and push 2cm into substrate at 2–3cm spacing. A group of five to seven stems provides an immediately coherent red colour mass rather than individual stems that take time to read as a colour event. Position in the background where stems can grow to full height without blocking midground plants.
2Position under the highest-light zone of the fixture — place Red Ludwigia directly under the centre or highest-output zone of the lighting fixture. Light intensity is the primary driver of colour — the same stems moved from a medium-light to a high-light position in the same tank will intensify in colour within two to three weeks as new growth develops under the higher intensity.
3Dose liquid iron from day one — begin iron supplementation immediately. Use a comprehensive liquid fertiliser with chelated iron dosed two to three times weekly from the day of planting. Do not wait to see what colour the plant produces without iron before adding it — iron deficiency takes weeks to become visually apparent and weeks to correct; consistent supplementation from the start prevents deficiency before it develops.
4Trim and replant on a four to six week cycle — once stems reach the surface or the top of the desired height zone, cut the top 10–15cm, strip lowest leaves, and replant immediately in the same group. The remaining lower stems produce side shoots below the cut point, increasing stem count and density in the group with each trimming cycle. A well-trimmed Red Ludwigia group after three months is substantially denser than the initial planting.
💡 Bonus Tip
Red Ludwigia planted immediately alongside or behind a group of Willow Hygro or Lemon Bacopa creates the most vivid warm-contrast pairing in the background stem plant section of the catalog — the deep red-orange of Ludwigia against the fine-textured green of Willow Hygro or the warm yellow-green of Lemon Bacopa produces an immediate colour event that reads from across the room. Both combinations share similar care and trimming schedules, making the mixed background group as practical to maintain as a single-species one.
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Browse more aquatic plantsPair Red Ludwigia with Willow Hygro, Lemon Bacopa, or Vallisneria for a complete planted background. Browse our Aquatic Plants collection.
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