Marsh ludwigia

Quick facts

Max height

40 cm

Growth rate

moderate

Difficulty

beginner

Placement

midground, background

Propagation

stem cuttings

Water parameters

Temperature

18–28°C

pH

5.5 to 7.5

Hardness

2 to 20 dGH

Cold water

tolerated (unheated setups)

Light and nutrients

Lighting

medium

CO2

not required, but boosts growth and color

Substrate

nutrient preferred

Feeding

feeds from both water column and roots (liquid ferts plus root tabs)

Substrate

What this plant roots into (or attaches to). The substrate affects both plant nutrition and water chemistry; see each linked page for full effects.

This plant feeds primarily from the water column, so substrate choice matters more for its fish-tank compatibility than for plant nutrition.

With fish

Plant-eating fish

safe with plant-eating fish (tough leaves or unpalatable)

Diggers (corydoras, loaches)

fine - root system or attachment style handles it

Root-disturbing fish

tolerates fish that disturb roots

Habitat

Native to temperate and tropical regions across the Americas, Europe, and Africa. The species (Ludwigia palustris) is one of the most widespread Ludwigia species, found in marshes, pond margins, slow streams, and wet meadows. The plant grows as a creeping to semi-upright stem with small, oval leaves arranged in opposite pairs. Submerged leaves are green to olive; under strong light, they develop reddish tones. The 'Super Red' cultivar (sometimes listed separately) was selected for intense red coloration under high light. Ludwigia palustris is one of the few red aquarium plants native to both North America and Europe, and it tolerates cooler water than most tropical red stems. Multiple subspecies and regional forms exist, contributing to confusion in the trade. The species crosses readily with L. repens, producing hybrids with intermediate characteristics. In the US and Europe, L. palustris grows wild in wetland habitats and can be collected legally from many locations during the growing season. The cold tolerance extends to brief frost exposure of the emersed form, which is unusual among aquarium plants.

Outdoor pond use

This species transitions to outdoor ponds well, not just indoor aquariums.

Outdoor pond zones (USDA)

4 to 10 (winter low around -34°C or warmer)

Below the minimum zone, the plant won't overwinter outdoors but can still be grown seasonally and overwintered indoors. Several pond-friendly species (water hyacinth, water lettuce, parrot's feather) are regulated as noxious in some jurisdictions; check the legality data on the profile before releasing anything to an outdoor body of water.

Care notes

Easy stem plant that provides red coloring without extreme demands. Grows in low to high light, though the red coloration only appears under moderate to high light with good iron supplementation. Under low light, the leaves stay green. CO2 is not strictly required but significantly improves the red color and growth density. Plant stems in groups of 5+, pushed into substrate. Growth is moderate, less aggressive than Hygrophila but steady. Trim tops and replant to propagate. The cut stems produce side shoots. Temperature: 15–28°C (tolerates cooler water than most red stems, useful in unheated setups). pH 6.0-8.0. Soft to hard water. Iron dosing (liquid fertilizer or root tabs with iron) is the single most important factor for red coloration; without iron, even under high light the plant stays green-brown rather than vivid red. A good entry-level red plant for keepers transitioning from all-green setups. Available from aquatic plant retailers as potted and tissue culture specimens.

Further reading

• How to cycle a fish tank
• Water chemistry for fishkeepers: pH, GH, KH, and what they mean