Red Ludwigia (Ludwigia repens) Photo: Show_ryu / Public domain

Red Ludwigia Care

Ludwigia repens · Onagraceae

🐾 Pet-safe 🎯 Easy ☀️ Bright with some direct sun 💧 Every 7 days
🕮 6 min read 🕓 Last reviewed: 2026-08-23

Care at a glance

Light
Bright with some direct sun
Temperature
18–28 °C (64–82 °F)
Soil
a nutrient-rich aquarium substrate (or attached to wood/rock)
Difficulty
Easy
Mature size
15–50 cm (6–20 in)
Pet safety
Pet-safe

The short version

  • Beginner-friendly and forgiving.
  • Give it Bright with some direct sun.
  • Water every 7–7 days.
  • Safe around cats and dogs.

The Red Ludwigia (Ludwigia repens) is an aquatic plant grown submerged in freshwater aquariums. It comes from North America and is rated Easy to keep, reaching 15–50 cm. Here is how to grow it underwater — lighting, substrate, CO₂, placement and propagation.

Also known asLudwigia repensルドウィジア・レペンス红水丁香Rote Ludwigie

📋Quick facts

Growth rateFast
Mature size15–50 cm (6–20 in)
Native regionNorth America
Plant familyOnagraceae
ToxicityNon-toxic
Air-purifyingNo
Ideal forbeginners, homes with pets

⚖️Pros & cons

Pros

  • Non-toxic to cats and dogs
  • Hard to kill; great for beginners
  • Fast, rewarding growth

Cons

  • Needs high humidity to look its best
  • Needs a bright, sunny spot

🐟Growing it in an aquarium

Keep the water at 18–28 °C. Stable, gently moving water and regular partial water changes keep it healthy; sudden swings in temperature or chemistry cause melting.

Light

Give it Bright with some direct sun-equivalent aquarium lighting. Low-tech tanks suit undemanding species; brighter light (and often CO₂) brings out the best colour and compact growth but also feeds algae, so balance it carefully.

Soil

Plant it in a nutrient-rich aquarium substrate (or attached to wood/rock). Rooted species are hungry feeders — use root tabs or a liquid aquarium fertiliser (and CO₂ for demanding types). Epiphytes like Anubias, Java fern and Bucephalandra must NOT be buried: tie or glue their rhizome to wood or rock, or they rot.

Its size and habit suit a spot in the foreground, midground or background depending on how tall it grows; trim and replant tops to keep it dense.

✂️How to propagate, step by step

Spring and early summer, during active growth, give the best success. Here is how to do it, step by step:

stem cuttings in water

  1. Choose a healthy stem and cut a 10–15 cm piece just below a leaf node with clean, sharp scissors.
  2. Strip the leaves off the lower third so no foliage will sit under water.
  3. Stand the cutting in a glass of room-temperature water with at least one node submerged.
  4. Keep it in bright, indirect light and refresh the water every few days.
  5. When the roots are 3–5 cm long (usually 2–4 weeks), pot it into moist mix and keep it a little humid while it settles in.

🔬Classification

Plant typeAquatic plant
GenusLudwigia
FamilyOnagraceae · Onagraceae
Native toNorth America

🩺Common problems

SymptomLikely causeWhat to do
Pale or faded leavesToo much direct sun, or a nutrient gapMove it out of harsh sun and feed during the growing season.
Melting or dissolving leavesShock from a new tank (common when settling in)Be patient — trim mushy leaves; new submerged growth usually follows.
Algae on leaves or glassToo much light or excess nutrients in the waterCut the lighting period, reduce feeding, and add algae-eating clean-up crew.

🩺 Plant Doctor →

🐛Pests & prevention

The usual indoor pests are spider mites (fine webbing, speckled leaves), mealybugs (white cotton-wool tufts), scale (small brown bumps), and fungus gnats (tiny flies from soggy soil). Inspect any new plant before it joins the others, wipe the leaves now and then, and let the topsoil dry to keep gnats away. At the first sign, isolate the plant, wipe or rinse off what you can, and treat with insecticidal soap or neem oil every week until it is clear.

🐾Is it safe for pets?

Good news for pet owners: the Red Ludwigia is considered non-toxic to both cats and dogs by the ASPCA. It is one of the safer choices for homes with animals, though eating any plant can still cause mild stomach upset.
Toxicity information is a general guide based on ASPCA data. If your pet or child may have eaten any part of a plant, contact a vet or poison control right away.

Frequently asked questions

Is the Red Ludwigia toxic to cats and dogs?

No — the ASPCA lists the Red Ludwigia as non-toxic to cats and dogs. Eating a lot of any plant can still cause mild stomach upset.

How often should I water a Red Ludwigia?

About every 7–7 days — let the top few centimetres of soil dry out first, then water thoroughly and drain.

How much light does a Red Ludwigia need?

Bright with some direct sun. Keep it out of harsh direct midday sun unless it is a full-sun plant.

Why does my Red Ludwigia have Pale or faded leaves?

Too much direct sun, or a nutrient gap. Move it out of harsh sun and feed during the growing season.

How often should I repot a Red Ludwigia?

About every 1–2 years, ideally in spring. Move up just one pot size when the roots fill the pot or creep out of the drainage holes.

How fast does a Red Ludwigia grow?

It is a Fast grower, with most of its growth in the brighter, warmer months of spring and summer.

How big does a Red Ludwigia get indoors?

Usually 15–50 cm indoors, depending on light, pot size, and how long you have had it.

Is the Red Ludwigia an air-purifying plant?

It is grown mainly for its looks rather than as an air-purifying plant, though all houseplants add a little greenery and humidity.

Is the Red Ludwigia easy to care for?

It is rated easy. It is very forgiving and great for beginners.

📚Sources & further reading

Care values reflect established horticultural guidance; toxicity is cross-referenced with the ASPCA.

Last reviewed: 2026-08-23

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