Overview & Origin
Ludwigia repens is native to North America, growing in marshes, ponds, and along stream banks across the southern and eastern United States, Mexico, and Central America. It belongs to the family Onagraceae (evening primrose family) and is one of the most commonly available Ludwigia species in the aquarium trade.
What makes Ludwigia repens special is that it's arguably the easiest truly red plant in the hobby. While many red plants demand CO2, extreme lighting, and precise nutrient dosing, Ludwigia repens produces attractive red coloration under nothing more than moderate lighting and basic fertilization.
How to Plant Ludwigia Repens
- Plant individual stems 2–3 inches deep in substrate, spaced 1–2 inches apart.
- Any substrate works — gravel, sand, or aquasoil. Root tabs help but aren't essential.
- Best as a background or mid-background plant. Grows 10–20 inches tall.
- Plant in groups of 5–10+ stems for the most visual impact — a dense cluster of red Ludwigia creates a stunning focal point.
Water Parameters
- Temperature: 68–82°F (20–28°C)
- pH: 6.0–8.0
- KH: 3–12 dKH
- GH: 3–12 dGH
Ludwigia repens is notably tolerant of hard, alkaline water — unlike many red plants that prefer soft, acidic conditions. This makes it suitable for aquarists with harder tap water who struggle to grow other colored plants.
Achieving Red Coloration
- Moderate light minimum: Under low light, leaves stay green. Moderate light (30–50 PAR) produces green tops with red undersides. High light (50+ PAR) turns the entire plant deep red to maroon.
- Iron helps: Supplemental iron deepens red color. Dose liquid iron fertilizer 2–3 times per week.
- CO2 not required: Unlike most red plants, Ludwigia repens develops good color without CO2 injection — one of its greatest advantages.
Popular Varieties
- Ludwigia repens 'Rubin': More intensely red than the standard form. Slightly more demanding but still beginner-friendly.
- Ludwigia repens 'Super Red': Deep, vivid red throughout the entire leaf. Requires higher light for best color but is still manageable without CO2.
- Ludwigia palustris: Very similar species often sold interchangeably. Nearly identical care requirements.
Maintenance
Ludwigia repens grows at a moderate pace — faster than Anubias or Crypts, but slower than Rotala or Hornwort. Maintenance is straightforward:
- Trim when stems reach the surface. Cut at the desired height — each cut produces 1–2 side shoots.
- Replant healthy cuttings to expand the group or share with other aquarists.
- Remove any leaves that turn yellow or brown at the lower portions — this is normal as the plant prioritizes upper growth that receives more light.
- Dose liquid fertilizer weekly and root tabs every 8 weeks for best growth and color.
Common Problems & Solutions
- Not turning red: Insufficient light. Move to a brighter spot or upgrade lighting. Even moderate light should produce red undersides.
- Dropping lower leaves: Normal — the lower portions receive less light as the plant grows tall. Trim and replant tops, discarding bare lower stems.
- Slow growth: May need more nutrients. Add root tabs and dose liquid fertilizer. CO2 also boosts growth rate significantly.
- Leggy stems: Not enough light. Increase intensity for more compact, bushy growth.
Frequently Asked Questions
Is Ludwigia Repens good for beginners?
Yes — it's the #1 recommended red plant for beginners. No CO2 needed, tolerates a range of water conditions, and produces red coloration under just moderate light.
Does Ludwigia Repens need CO2?
No. It's one of the few red plants that colors up well without CO2 injection. CO2 will accelerate growth and intensify color, but it's not necessary.
How fast does Ludwigia Repens grow?
Moderate — about 1–2 inches per week under good conditions. Slower than Rotala or Hornwort but faster than Anubias or Crypts.