How to prune azolla filiculoides

As needed during the growing season (spring–autumn). Remove excess Azolla by scooping or netting it from the water surface. Dispose of material in compost or garden waste — never into waterways. Leave some coverage if using it for nitrogen fixation or wildlife shelter.

As needed (often weekly in warm weather). Azolla filiculoides (water fern, fairy moss) is a free-floating aquatic fern that requires no pruning. Control its spread — it can double its mass in days under good conditions — by physically netting out excess plants. In many regions it is invasive; check local regulations. No cutting or trimming is needed or useful.

Remove excess Azolla by scooping or netting it from the water surface. Dispose of material in compost or garden waste — never into waterways. Leave some coverage if using it for nitrogen fixation or wildlife shelter.