Heath I would spray it if the leaves are still green. As Bill says, the roots are getting nutrients for winter stores.

After the hard freeze this Thursday I would not spray it.

You are right on the razors edge of being too late, BUT...... I think there is still a chance that enough spray will get transferred to kill a bunch of it. It might not get as good of kill as earlier in the fall but if it were mine and I wanted it gone I would spray it.

Here is my reasoning. You have the chance of it succeeding or failing or something in between. If it doesn't work you are out a little money but not a huge amount. If you don't spray you already know the stuff will come on like gangbusters in the spring. You can spray it in the spring, but you have to wait till a significant greening up happens to get enough surface area to get the chemical translocated. Plus you are heading into hotter weather where the dieing biomass could cause problems. If you wait too late in the season you could actually cause some DO problems if you treat too much of it at once.

I would take a chance on it working. When we spray Johnsongrass we need an hour before it rains (and potentially washes the chemical off). We consider it rainfast in an hour and I have actually sprayed a field when it started to rain in the middle of the field. Anything that hit dry leaves we had control. Anything that hit wet leaves we did not. The plants that started getting wet with drops of rain had partial control. If you get the glyphosate on the leaves and the plant has not completely shut down, it will translocate into the roots and kill. I don't think the spatterdock has completely shut down "here". After Thursday and Friday's hard freeze, then likely the leaf tissue would be damaged enough to maybe not work.

I would risk wasting a few bucks as opposed to having to deal with it next spring. Worst case you waste a few bucks and still have to deal with it next spring.

Once you realize how much reserves those huge roots hold, hand removal is only good for immediate fishing access. To kill it mechanically you would have to keep the leaves repeatedly removed each year for about three years probably. My roots kept trying to grow in the too deep water for two years after skipping a year after the pond rebuild. So it was three years later that they finally gave up. Those are tough plants.

John

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