Azolla Filiculoides (Azolla filiculoides) Care Guide

A tiny floating fern with overlapping scale-like leaves that form dense mats on the water surface. Can turn from green to reddish-brown under strong light, and is one of the fastest-reproducing aquati…

Overview

Azolla filiculoides is an aquatic plant in the family Salviniaceae. A tiny floating fern with overlapping scale-like leaves that form dense mats on the water surface. Can turn from green to reddish-brown under strong light, and is one of the fastest-reproducing aquatic plants known.

Taxonomy

• Family: Salviniaceae
• Genus: Azolla
• Scientific name: Azolla filiculoides
• Other names: Fairy Moss, Water Fern

Habitat

A floating fern native to warm temperate and tropical regions of the Americas, introduced widely across Eurasia, Africa and Oceania. Hosts the symbiotic cyanobacterium Anabaena azollae in specialised leaf cavities, enabling nitrogen fixation from the atmosphere.

Growth requirements

• Light: low (≈30-50 PAR at substrate)
• CO2: optional (CO2 improves growth and coloration)
• Temperature: 15-28 °C
• pH: 5.5-8
• GH: 2-15 °dGH
• Nutrient demand: low
• Growth rate: fast
• Difficulty: beginner

Placement

• Recommended placement: floating at the surface
• Maximum height: 2 cm
• Trim every: 5 days

Propagation

In cultivation the plant is propagated by vegetative division or fragmentation.