Eurasian Millfoil is getting in the way of our slalom course !

[RichardDoane]

Has anyone out there come up with a chemical kill for these problem weeds ? The grass eating carp are doing their best, and the aquashade dye makes the lake look pretty, but the darned weeds are getting worse. Any suggestions ?

[jbougie]

SONAR

[block]

Try Aquacide. This product is a 2-4D product.

  Call me for more information. 423-253-4061.

 

Johnny

[DW]

I have had some luck with Copper Sulphate even though it is not the best rated chemical treatment for Milfoil.

[Than_Bogan]

Unfortunately, I am fairly knowledgeable on milfoil treatments (though I'm not so good at spelling them).  The main herbicide options you have are:

Floridone (brand names include SONAR).  This is a "systemic" herbicide: you must treat the entire lake with it and reach a certain concentration throughout.  For a dug-out waterski pond, this probably makes no difference, but in a larger lake it can mean WAY more chemical introduced into the environment in total.

Diquat Dibromide (brand names include Reward).  This is a "contact" herbicide -- it only kills the weeds it actually lands on.  Anything that misses on the way down bonds to sediments in such a way that it is biologically unavailable.  (This means you could eat that sediment and none of the bad things that resulted would be caused by Diquat Dibromide.)  In my opinion, the safety characteristics on Diquat are BY FAR the best, but it can't really be used to treat a true infestation on any but the smallest ponds.

2,4D (brand names include Aquacide).  This is also more of a systemic herbicide, but I know a lot less about it because it is illegal to deploy into water here in Massachusetts (as are Sterile Grass Carp, btw).  However, I know some lakes in Vermont had great success with it.

The fundamental issues with herbicides are safety and frequency of treatment.  Most likely you'll have to do it again about every two years.  And of course, you are pouring toxic substances into your water, although if applied by an expert the safety characteristics on all three of these are as good as could possibly be hoped for.  I believe all three are approved near well heads and in irrigation water, though usually there are "blackout" periods after application where certain uses must be avoided.

There are all sorts of other "interesting" treatments for milfoil, some of which have had great success in a handful of spots, but haven't proven consistently effective.  These include milfoil weevils and water circulators (NOT aerators: circulators).  And in a small pond, just plain chopping it down on a regular basis can work.  (Don't try that on a new infestation in a larger pond -- the fragments become new plants and you spread it orders of magnitude faster!)

Unfortunately it's VERY hard to get reliable, unbaised information on milfoil treatment.  So many parties have vested interests or agendas, and all sorts of "whack jobs" are more than happy to exaggerate the potential downsides of any given treatment.

GOOD LUCK!  (And welcome to the fraternity...)

[skidawg]

Take up golf!

[RichardDoane]

Even though the SkiPark has a 6 hole course surrounding it, I refuse to take up golf because it seriously lacks acceleration. Someday when I'm old and crippled from shortline slalom and hitting the jump, my tune may change. Thanks for the "weed info", I'll pass it along. It's the BroHo site that's getting a little "weedy", but it still skiing good.

[DW]

We have also had good luck with Reward on a 110 acre lake.  2,4D also works and is used in many states to treat Milfoil.  As mentioned, good luck.

[Than_Bogan]

golf has plenty of acceleration if you're the ball...

[billgalli]

There are several issues to consider. The 2,4-D products work well, if they are legal in your state. The Aquathol based products work great in most lakes, when applied properly and you do not get a lot of wind action for at least a day after application. Aquathol comes in a liquid formulation and granular. The granular is more costly but it gets the product down to the part of the plant where it is most effective. The draw back to Aquathol is it is slow especailly when you have established and mature weeds. Reward/Diquat does not work well in shaded lakes.

The fastest way to rid the weeds at this point in the season is physical removal.

The most common mistake in using Aquashade or any other shade is not getting it into the lake early enough in the season. The first of Feb. is not to early to start in most regions. The shading products work best when used as a preventive treatment. I have found most lakes need between 27 to 30 gallons at that point to establish the best shading possible.

 Bill Galli

[RichardDoane]

I think our raking, and physical removal may have exasperated the weed problem. If the little pieces that get cut loose and float away, how quickly do they regrow ? Doesn't the plant have to be rooted to the bottom to live ? We need some waterskiers with "green thumbs", but appreciate all the advice.

[Than_Bogan]

That's a very real possibility (that you made it worse).  Milfoil does something kinda cool (from an evolutionary biology viewpoint) called vegetative growth: it can grow tendrils from a fragment as short as 1" and eventually re-attach itself to the ground.  I believe the timeframe on that is a few weeks, although I don't recall for sure.

Milfoil can be effectively hand-pulled if you grasp at the base and yank out the entire root and remove the entire plant/root combo from the lake.  But this is VERY labor intensive, and can only really be used to clear a small shallow area, like maybe around the starting dock.

Btw, what you need is someone with a Brown Thumb, and I'm your man for that.  You bring me any plant and ask me to take care of it, and it'll be dead in a matter of days!

Interesting note about Diquat not working in shaded lakes.  I had never heard that before.