Floating ludwigia

Ludwigia helminthorrhiza

Also known as White-root floating ludwigia

FreshwaterFloatingCuttingsFragmentation

Floating ludwigia (Ludwigia helminthorrhiza) — (c) Patricio Novoa, some rights reserved (CC BY) · cc-by

Care at a glance

Light: High light
CO2: No CO₂ needed
Temperature: 72–82°F; 22–28°C
Max height: 2 in; 5 cm

Growth rate: Medium
Placement: Floating
Type: Floating
pH: 6.0–7.5
Hardness: 2–12 dGH
Spread: 9.8 in (25 cm)
Nutrient uptake: Water column
Growth region: Submersed or emersed
Difficulty: Medium
Family: Onagraceae
Origin: A floating primrose willow from still and slow fresh waters of tropical Central and South America, spreading across the surface of ponds and flooded margins.

Overview

Floating ludwigia is a floating primrose willow that forms mats of rounded green leaves at the surface. It is of medium difficulty.

Did you know

The species name helminthorrhiza means worm-shaped root. It is a nod to the pale, spongy roots that let floating ludwigia breathe while it drifts.

Caring for floating ludwigia

Let floating ludwigia drift at the surface instead of planting it. It feeds straight from the water column, so a liquid fertilizer covers it, and it needs no added CO2. It mops up nutrients that would otherwise feed algae.

Give it high light from a strong planted-tank LED. Bright light keeps the rounded leaves compact and flushes them reddish. It grows well from 72 to 82°F (22 to 28°C).

It grows at a medium pace, and each plant spreads to about 25 cm across. Thin the mat regularly so it does not shade the rooted plants underneath. Any length of stem you cut off grows into a new plant, and pieces pulled off a clump keep growing.

Good to know

Floating ludwigia is a member of the evening primrose family, the same group as the stem-plant ludwigias. The white, spongy structures that dangle beneath each leaf cluster are pneumatophores. These air-filled breathing roots both float the plant and take in oxygen.

In the wild

Floating ludwigia comes from still and slow fresh waters of tropical Central and South America. It creeps across the surface of ponds and flooded margins, and it can also climb onto wet edges as a marginal plant.

Common questions

Does floating ludwigia need to be planted in the substrate?

No. Floating ludwigia floats at the surface and takes its nutrients straight from the water.

Does floating ludwigia need CO2?

No. Floating ludwigia grows well without added CO2.

How much light does floating ludwigia need?

Floating ludwigia needs high light from a strong planted-tank LED.

How do you propagate floating ludwigia?

Floating ludwigia propagates by cuttings and fragmentation. Any length of stem cut off grows into a new plant. Pieces that break off keep growing, so pulling a clump apart spreads it.