Also known as Azolla · Duckweed Fern · Fairy Moss
Water Fern (Azolla filiculoides) is a free-floating aquatic fern known for its rapid growth and nitrogen-fixing capabilities, forming dense mats on water surfaces.
At-a-glance light, water, soil, and growing conditions from plant data
Full Sun to Partial Shade
75% intensity
Prefers bright, indirect sunlight or full sun. Excessive shade can reduce growth and nitrogen-fixing ability.
Constant Moisture/Submerged
100% intensity
Requires consistently wet soil or to be submerged in 1-5 cm of clean, fresh water.
None (aquatic)
50% intensity
Moderate to Warm
50% intensity
Prefers temperatures between 15°C and 30°C. Sensitive to frost; protect from freezing conditions.
Aquatic
50% intensity
Low/Nitrogen-Fixing
25% intensity
Does not typically require fertilizer as it fixes its own nitrogen. Use very dilute, low-nitrogen fertilizer only if growth is poor.
Safety information from plant toxicity data
| Attribute | Value |
|---|---|
| Toxic for humans | No 0/5 intensity |
| Toxic for pets | No 0/5 intensity |
None
Key traits and growing stats from plant data
Watering, pruning, propagation, and repotting details from plant data
Azolla filiculoides thrives in constantly moist to submerged conditions. Maintain a water depth of 1-5 cm in its container or pond.
Ensure the water is clean and free of pollutants, as it is highly sensitive to poor water quality. Avoid letting the water level drop significantly.
Pruning is rarely necessary for Azolla filiculoides. Its rapid growth naturally thins out dense mats.
Excessive growth can be managed by scooping out portions of the plant to prevent overcrowding and ensure adequate light penetration for other aquatic life if grown in a pond.
Azolla filiculoides propagates rapidly through fragmentation. New plants develop from existing fronds as they grow and break apart.
Simply allow the plant to multiply naturally; manually separating larger clumps can also encourage faster spread.
Azolla filiculoides is typically grown in ponds or aquatic environments and does not require repotting in the traditional sense. If grown in a container, it will quickly fill it and may require thinning out to manage its rapid growth and prevent it from becoming overly dense.
Identify plants like this with ePlant AI
Snap a photo to get care tips and match similar species on the go.
Monthly activity intensity for bloom and fruit across both hemispheres.
Flowering & fruiting calendar
Flowering & fruiting calendar
Photos of Water Fern (Azolla filiculoides)
Common names and botanical synonyms
Botanical classification
| Rank | Name |
|---|---|
| Kingdom | Plantae |
| Division | Tracheophyta |
| Class | Polypodiopsida |
| Order | Salviniales |
| Family | Salviniaceae |
| Genus | Azolla |
| Species | Azolla filiculoides |
Similar in genus Azolla
Answers based on plant encyclopedia data
