How long do I have to get roots with Navigate? My Speader needs a new switch and the ATV needs a battery. I'm still on a trachea so I'll have to get one of my buddies to do it.

As most systemic herbicides you need to use the product when the plant is actively growing. Usually in the spring is best. When the plants top out you will have a harder time killing them. Remember Navigate is 24D and only kills broadleafs. What plant you going after?

Aquatic control sold me Navigate to kill coontail.

It is supposed to kill coontail but remember coontail is a floating plant and if it floats off the area of treatment it will not work. It does not have true roots but these things called holdfasts. Hopefully you treated it when it was being held in place or a shallow area.