Mosquito fern, Feathered mosquito fern, Water fern, Asian watermoss
Azolla pinnata
🌿 Morphology
🌞 Growing conditions
🌍 Origin and family
🌾 Uses
Warning: Despite the care taken in writing this sheet, it is essential to cross-reference sources before using or consuming any plant. When in doubt, consult a qualified professional
Permaculture uses
Azolla pinnata is highly valued in permaculture as a nitrogen fixer, acting as a green manure and biofertilizer. It can be used as animal feed, especially for poultry and fish. Its rapid growth enables it to suppress weeds in rice paddies. It can also be utilized for water purification, removing pollutants such as excess nutrients and heavy metals. Some cultivars might be more cold-hardy or drought-resistant.
Permapeople description
Azolla pinnata is a small aquatic fern native to tropical and subtropical regions. It is often used as a biofertilizer.
Botanical description
Azolla pinnata is a small aquatic fern, typically 1-3 cm in size, forming floating mats on the surface of the water. The leaves are small, scale-like, and arranged in two rows along the stem. They are typically green to reddish-brown, depending on environmental conditions and nutrient availability. The plant harbors a symbiotic relationship with the nitrogen-fixing cyanobacterium Anabaena azollae, which resides within cavities in the leaves. Reproduction occurs both vegetatively through fragmentation and sexually via spores produced in sporocarps.
Companion planting
Azolla is commonly used as a companion plant in rice paddies, where it fixes nitrogen and suppresses weeds. It can also be used in aquaponic systems to remove excess nutrients from the water. Due to its rapid growth, it can potentially outcompete other aquatic plants if not managed carefully.
Propagation methods
Azolla pinnata readily multiplies vegetatively through fragmentation. Small fragments of the plant can quickly expand to cover a large area of water. Spores are produced but are less common and less reliable for propagation.
History and traditions
Azolla has been used as a green manure in rice cultivation in Asia for centuries, particularly in Vietnam and China. Traditional medicinal applications are less documented, but some cultures use it for its purported anti-inflammatory and wound-healing properties. It has been studied as a potential biofuel source and carbon sequestration agent.
Usage calendar
Azolla grows most rapidly during warm months (spring and summer) when temperatures are optimal. It can be added to compost at any time. Harvesting for animal feed or green manure is best done regularly during periods of rapid growth. Planting (introducing new fragments) is best done in spring or early summer.