The New Zealand Plant Conservation Network

How can I remove it from my pond? Has it got a finite life cycle and will die naturally? I have quite a thick covering in a large pond that we have been dredging to remove it, but obviously fighting a losing battle (although it does make a good mulch for my roses) I am just afraid that my nature pond, home to dragon flies, frogs,etc is going to be a red festering mess

Azolla is a natural feature of still waterways. It is ecologically useful because it helps shade the water during the summer and usually thins out during winter. In areas where it is frosty the pond can be completely clear in winter. Shading the water is important as cool water retains more oxygen and therefore provides better habitat for, fish, frogs and dragonflies.

Hi Ann, as Astrid says, it is a useful species for cooling water and also removing water-borne nutrient. Minimising input of nitrogen and phosphorous into your pond via sediment traps and margin plantings can help. Also planting other shading sedges, rushes and shrubs. If it is forming thick stinking masses when it decomposes that is a sign of the pond being unhealthy and an almost start-again point.

Thankyou both Astrid and Mike, I don't feel so bad now. Thankyou for the tips. The reason it has gone berserk is I have extensive rose gardens, I fertilise well and the storm water run off is directed to the dam...pond...and obviously its become an mazing nutrient rich soup. However, with a bit of ingenuity my husband and I rigged up a dredge and we can skim the top off the pod and we are using it to mulch the roses. If we do it once a month or so, we have hit on a very cost effective way of putting the nutrients back in the soil. We also had to remove my two huge willow trees so the shade was lost and the sun has helped the Azolla. Well its all a learning curve!