The water level was down, I then had two 4" gully washers 3 weeks apart that reduced visibility down to less than an inch. The milfoil never made it to the surface before it lost the light it needed to grow. The lack of sunlight over a prolonged period killed it off. Plants need light, nutrients, and the right temperature to grow, take away any one of those, and they won't thrive.

Have you thought about using pond dye right after ice out to choke out the light while the milfoil is still laying down on the bottom?