Pond Boss Forums AQUATIC VEGETATION Identifying plants Help with problem weed

I am helping a man clean a 2 acre pond that is completely covered with this plant. It is on the surface and has completely covered the pond. It has a leaf that looks like a clover with scalloped edges. When it is green it blossoms up and it puffy, looks like little broccoli heads. It has roots about 2-3 inches down into the water. The owner has seen it in earlier years, but never has it covered the whole pond. I think I have found a picture on this site http://plants.ifas.ufl.edu/azocar.html . They call it Carolina Fern.

Where does it come from and how can I treat it or even prevent it from coming back.

There is a great product called Sonar that you can use as a water column treatment. You have to keep water from leaving the pond for at least 40 days and there is also and irrigation restriction. You would also not want to use it this late in the year. Another product that you could use would be Reward and add a surfactant to do a surface treatment, but this will not be as effective as Sonar.

Does anyone know where this plant comes from?

Fred

Assuming it is azolla, it's quite common plant on ponds in warm climates, no big surprise it can migrate on the foliage of birds so it's something of a hitchhiker...

It can be quite beneficial in certain circumstances, reducing evaporation during droughts quite considerably.... dredge it out and you have a very effective mulch material. That it has built up indicates you have had low rainfall at a guess and fertility is rather on the high side encouraging it to explode in numbers....

On small ponds it's fairly easy to spray it to one side and net it out, on a big pond it's quite possible it could become a problem forming inches thick... You might want to consider how much fertility has been going into your pond lately, it could be time to cut down on the fertile 'inputs' and dredge, if you find a chemical way to kill it, it's going to dump a horrific amount of fertility back into the pond, all to go off and start up secondary pollution....

If you could set up a pump and filter it out you would have quite a lot of 'mulch'

It might take just one big rain storm to blast the bulk of it out of a pond when it overflows... In a more Northerly climate, azolla is usually killed out by severe freezes

Regards, andy

Thanks for the info. We had been fairly successful, moving back to one edge of the pond with ropes and 2 2x6's that make a 32 ft scraper, then we scoop it up with pool cleaning nets. It is a lot of work. Now I have to go around the edges and get the left overs out of the reeds, etc.

Fred