Ludwigia repens

Quick facts

Max height

45 cm

Growth rate

moderate

Difficulty

intermediate

Placement

midground, background

Propagation

cuttings

Water parameters

Temperature

20–28°C

pH

6.0 to 7.5

Hardness

1 to 18 dGH

Light and nutrients

Lighting

medium

CO2

not required, but boosts growth and color

Substrate

any

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 the southeastern United States and Mexico, found in marshes, pond margins, ditches, and shallow water. The species (Ludwigia repens) is one of the most popular and easiest red-green stem plants in the aquarium hobby. Stems grow upright with opposite pairs of rounded to oval leaves: the upper (newer) leaves are reddish under good light while the lower (older) leaves are dark green, creating an attractive gradient effect along each stem. This two-tone coloring is the species' signature look. The plant grows both emersed and submerged; nursery specimens are typically grown emersed and transition to submerged growth over 1-2 weeks after planting. In the southeastern US, wild L. repens is a common wetland plant found in roadside ditches, pond margins, and slow streams. It can be collected legally for aquarium use in many areas. The species is closely related to L. palustris and the two hybridize freely, producing offspring with intermediate traits. Many plants sold as one species may actually be the hybrid.

Outdoor pond use

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

Outdoor pond zones (USDA)

6 to 11 (winter low around -23°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

One of the easiest red-green stem plants for beginners. Moderate light produces the red-green gradient that makes this species popular; under low light, the red fades to olive-brown. CO2 is not required but improves color intensity and growth rate. Plant stems in groups of 5-8. Growth is moderate to fast; trim tops weekly and replant to maintain a dense group. The cut lower stems produce side shoots, creating bushier growth with each trim cycle. Iron supplementation (liquid or root tabs) supports the red pigmentation. Nutrient demands are moderate; basic liquid fertilizer keeps the plant healthy. Temperature: 20–28°C. pH 6.0-8.0. Tolerates a wide range of hardness. One of the best 'first red plants' for keepers who want color without the demands of Rotala rotundifolia or Alternanthera. The red-green gradient looks natural and attractive without the need for the perfect high-tech balance that more demanding red plants require. Widely available from pet stores, online retailers, and hobby swaps. Propagation by cuttings is reliable and fast.

Further reading

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