THE BEST weed control is achieved by spraying weeds when they are actively growing and at the right stage. This is commonly known as the rosette stage of the weed. Docks should ideally be 6-10' high or across and without any seed head showing.
This gives the best opportunity for the fully systemic weedkillers like Doxstar, Pastor and Forefront to get translocated down to the root which is vital for long term control.