Duck weed. Friend or foe?

I have a wildlife pond which is well planted up and has beautifully clear water but I feel it is spoilt by masses of duck weed. I spend ages scooping it out but it gets tangled round the plants and always comes back. Recently someone told me that it would be helping to keep my water clear and that I should leave it. Is this true? If not, has anyone got any ideas about keeping it under control other than by netting it?

Keen to hear your thoughts.

 

I've always used a net to skim it off, Chrysocolla, and that's the advice given by the RHS too. I can't see what benefits there would be in keeping it, as I can't see how it would be keeping your water clear.... Oxygenating plants wil help do that, though. Do you have any of those?

And welcome, BTW!

 

Duckweed out competes pond algae for available light so in this respect it does help keep the water clear. It thrives in water with high nitrogen and other nutirient content so perhaps the best way to control it other than by regular skimming is to examine the water quality in the pond.

More background info from Mobot: Vegetative Growth of Duckweeds

 

I agree with frogesque on this, it must take up some nitrogen from the pond water and also shading the water, so stopping the growth of algae.
If you skim it off regually you are removing nitrogen from the pond, and its much easier to remove than blanket weed or green water.
In fact I think you can buy Azolla, (think thats how its spelled) which is a floating fern, to do exactly the same thing.

 

It's also great for the compost heap! :D

 

Thanks for your thoughts. I didn't realise that it would take up nitrogen. I have so much of it that you might be right Frodesque and I do need to look at the water quality. To be honest, I thought if the water was clear and full of life it must be OK. That would explain why I have another pond that never gets it. The main problem with scooping is that I do have tons of oxygenator plants which have grown to the surface and the duckweed gets all mixed up in it making it very difficult. At the moment, when it is really bad, I go into the pond with some shears and try to cut it off below water level, then remove both together. Not my favourite job and as the pond is clay lined, it stirs it up for days.
Chrysocoll

 

hey i know this is an old thread but was wondereing if frogesque, you could possible email that vetative growth of duck weed thing my friend would be well interested and has not got a computer, i could then mail it to her!! many thanks