Dividing or getting rid of yellow flag

[galap01]

My pond is 10 years old now and my yellow flag iris are in desperate need of dividing.  I have a rubber liner.  I tried cutting some of the narly roots out in the spring and didn't get too far.   What is the best time of year to do this and the best approach?  A local nursery /pond expert told me this weekend I can use Round Up(I have fish).  He took me out back to their 'breeder pond' and showed me where he sprayed all his overgrown cattails and brush in the pond.   He recommended spraying now, and then in spring when I do clean-up I could remove the dead roots.   Is this the best/only approach?

[Esther]

UM, I am not an expert at all on this topic,  but about gagged when you said to spray ANYTHING around the pond. My aunt had a Koi pond that had a canvas cover 8-9' up there. The spiders would climb the legs and put webs all over the place. So when my aunt had gone to the mall, Uncle sprayed for the spiders. Yup, when she came home, the Koi were all gasping for air and yup, they all died. 

[Julles]

Hee hee...I Googled, and the first that came up was "Noxious Weed Control".  Guess you DO have an invasive plant there!

Sounds like the plants are not in pots?  If they were, it would be relatively easy to pull up the pots and remove the escaping overgrowth.

Re the RoundUp, from what I understand, if you are careful to spray ONLY on the foliage, the leaves will absorb the poison and bring it down to the roots, eventually killing the plant.  It stays within the plant's walls, and doesn't dissipate into the water.   And, supposedly, RoundUp and other such chemicals decompose very quickly when they come in contact with soil...and perhaps water, too.

That said, I would certainly NEVER use such a chemical around my pond or fish or plants. 

Looks like you're back to pulling it up and hacking. 

You might try pulling all of it up and disposing of it all, except for one small tuber, and start all over again from that one tuber.  Easy and quick.  You'd have to wait a little for it to regrow, but that's better than being totally overrun.

Oh, and welcome to the forum.   

[Esther]

If you decide to use Roundup, how about brushing it on the foilage carefully, instead of spraying?

The plants I have in the pond are in pots sitting inside of a round preform. I contains the roots that jump the pots. I'll have to show you the mess we had with yellow flag, mini cattails and Bog Bean. The plant roots that had jumped the pots had totally filled the preform and my hubby cut the roots apart to get to the pots with a Sawzall. I retrieved a few sprouts and replanted them and I spose in 7-8 years, we'll have to do it again.

[Zoe]

That picture looks like what my umbrella palm looked like at the daycare pond.  It took two big men to take it out of the pond and they set it on the side of the road. When I was getting ready to leave after working there the palm was gone!  The root system was huge and was causing havoc on the intake of the pump.  We were always cutting the roots away. 

Cindy

[galap01]

Thanks for the advice so far.  The plants are not in pots so it sounds like I'm in for a boat load of fun   Guess I should have asked this question years ago, but at the time I was wanting my pond to grow-up BIG! The sawzall sounds interesting.  Still totally afraid I will cut the liner and have a bigger problem on my hands.  The guy who recommended the Round up says it does indeed breakdown when it comes into contact with water.  Guess I don't know how it works so well on garden weeds once it rains and they are soaked.  Looking like I have 3 choices.  1. Use roundup, potentially kill the fish. (*BTW carefully brushing on sounds like a great idea)  2.  Manually try and cut/rip them out - which could take days as I have 3 very large clumps(additionally will need to drain at least 1/3 off the top of pond).  3.  Do nothing and bulldoze the entire pond in 5 years?   Thanks for all your help.  If I can figure out how, I'll post some pics.  would love to share.   My 3 clumps have got to be at least the size of that picture.  Ugh, I'll be in bed with back pain for days. 

[Kittyzee]

Since we farm and use round up on our round up ready soy beans (and hubby mixes me up some for my sprayer when he's mixing his) I can tell you that when sprayed on a plant it should be on it for at least an hour before coming in contact with water--in our case, meaning rain.  So if it's going to rain soon, we don't spray.  When round up comes in contact with water, it's neutralized and useless for weed control.  I'm sure if you googled it, you'd find a lot more about it too, maybe even some scary stuff....    

[Julles]

Round Up would only solve part of the problem, anyway.  The plants may die, but you would still have to wrestle with the very heavy and unwieldy root mass. 

Oh, and I'm sure you know this...don't take the SawzAll into the pond.   

[galap01]

Thanks for all those who replied.  I may have found my own solution.     I was in the pond this glorious weekend in MN doing some pond shutdown.  I started pulling at the roots with my hands.  While not easy, just pulling and digging with my hands, I was able to make progress on 1 of my 3 big issues.   I thought it would be easiest getting rid of the roots where no water was with them.  Turns out, while fully wet..and maybe hard to see...just pulling with my hands and digging out those blasted roots...was very successful.  Not fun mind you, but it works. 

[Michiponder]

Sounds like you have found out the hard way that it is best to do annual maintenance on yellow iris.  I found out by leaving a 25 gallon pot of yellow flags in a pond for 5 years.  When I had to remove it I found that it had split the pot and also grown over the top ending up being over 2 1/2 ft. in diameter and 2 ft. tall.  Ended up chopping it into pieces to remove it.  I also have a 2 ft. band of yellow flag running around several of my earth bottom ponds for erosion control.  The root mass after 15 years is quite substantial.  Those are controlled by mowing with the lawn tractor regularly. Even with regular mowing the seeds started escaping to the woods and have taken hold at any moist and partly sunny spot available.  They  are very invasive in the right environment and need regular maintenance to contain them.  You may want to try some of the pond herbicides used for emergent plants, but be very careful about the dose rates.  Have had to use them here a few times and they worked fairly well without effecting my fish.  I usually purchase mine at local farm supply stores.