Red Water Fern Plant Care

Red Water Fern (Azolla filiculoides) belongs to the Salviniaceae family within the Azolla genus. Red Water Fern is native to warm temperate and tropical regions of the Americas, and has been introduced to Europe, North and sub-Saharan Africa, China, Japan, New Zealand, the Caribbean, and Hawaii. Red Water Fern is also known as Mosquito Fern, Water Fern.

Red Water Fern displays a floating aquatic fern growth habit, reaching up to tall with a spread of approximately 1 ft. Red Water Fern produces tiny inconspicuous sporocarps.

Azolla filiculoides requires watering every 3–7 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.

Red Water Fern thrives in full sun to partial shade.

Azolla filiculoides grows best at temperatures of 60–80°F. Red Water Fern prefers humidity levels of 60–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Nutrient-rich, muddy soil or water with high organic content. Good drainage is essential for Red Water Fern to prevent waterlogging, which leads to root rot and fungal issues.

Feed Red Water Fern every month during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.

Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Not applicable, grows floating on water. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.

Red Water Fern can be propagated through spores, division. Similar propagation techniques also apply to carolina azolla plant care, which shares the same genus.

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Red Water Fern is susceptible to generally pest-free. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Red Water Fern grows outdoors in USDA Zone 7a – 11b. It survives winters down to planting zone 7a. Red Water Fern is native to warm temperate and tropical regions of the Americas, and has been introduced to Europe, North and sub-Saharan Africa, China, Japan, New Zealand, the Caribbean, and Hawaii.