TankBud

Dwarf water lettuce

Pistia stratiotes

Also known as Water lettuce, Nile cabbage, Water cabbage

FreshwaterFloatingRunnersSide shootsPlantlets

Invasive. Highly invasive in warm waterways and restricted or banned in several US states. Never release into the wild; dispose of in the trash.

Dwarf water lettuce (Pistia stratiotes)
Kurt Stüber [1] · CC BY-SA 3.0

Care at a glance

Light
Medium light
CO2
No CO₂ needed
Temperature
72–86°F
22–30°C
Max height
3.9 in
10 cm
Growth rate
Fast
Placement
Floating
Type
Floating
pH
6.0–7.5
Hardness
3–12 dGH
Spread
5.9 in (15 cm)
Nutrient uptake
Water column
Growth region
Submersed or emersed
Difficulty
Beginner
Family
Araceae
Origin
Pantropical (debated, likely South America/Africa)

Overview

Dwarf water lettuce is a fast-growing floating plant and a good pick for a beginner. It floats as a rosette of velvety leaves above a long curtain of fine, feathery roots.

Did you know

Water lettuce is one of the oldest aquatic plants on record. Ancient Egyptian and Greek texts described it thousands of years ago.

Caring for dwarf water lettuce

Drop dwarf water lettuce on the surface. Its trailing roots pull nutrients straight from the water, so it needs no substrate, and a liquid fertilizer feeds it. It needs no CO2 and does fine under medium light.

It works as a nitrate sponge and gives shade to shrimp and fry. It multiplies fast, budding off new daughter rosettes on short runners. Scoop out handfuls regularly so it does not cover the whole surface and block light to plants below.

Condensation from a lid and strong surface spray are the classic killers. Water sitting on the crown makes the leaves melt and rot, so keep a gap under the lid and gentle surface flow. It handles 72 to 86°F (22 to 30°C).

It is a regulated noxious weed in some regions. Never release it into the wild.

Good to know

Pistia stratiotes is the only species in its genus. It is an aroid in the arum family, Araceae, alongside Anubias and Cryptocoryne, and it is not related to lettuce at all. It produces tiny, easily overlooked greenish flowers. Fine water-repellent hairs cover the leaf surface, trapping air and keeping the rosette buoyant and dry on top.

In the wild

Water lettuce drifts on still and slow-moving ponds, ditches, lakes and river backwaters across tropical and subtropical waters worldwide. Its exact native range is debated, but it is now naturalized nearly everywhere warm.

Common questions

Does dwarf water lettuce need to be planted in the substrate?

No. Dwarf water lettuce floats at the surface and takes its nutrients straight from the water.

Does dwarf water lettuce need CO2?

No. Dwarf water lettuce grows well without added CO2.

How much light does dwarf water lettuce need?

Dwarf water lettuce wants medium light. A light sold for planted tanks covers it.

How do you propagate dwarf water lettuce?

Dwarf water lettuce propagates by runners, side shoots and plantlets. New plants form along its runners and break away to float on their own. Side shoots bud off and float free.

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