Question
Hello,  I would like to know the fastest way to kill large willow and evergreen trees without having to cut them down first and hopefully not detected to easily that the tree has been tampered with.  It's not my neighbors. haha  The bottom line is I want to kill them fast.  thank you

Answer
Two methods that are less noticeable are basal spray and hack and squirt. Basal sprays are applied in the late fall on the lower trunk of the tree and the effects are noticed next spring when the tree does not leaf out. They work best on thin barked trees but will work on thicker barked trees. The herbicide to use is Triclopyr
(Pathfinder) Pathfinder is a "Ready to use" product that is formulated and dosed correctly for this type of application. Apply Pathfinder at 100% strength as directed.

Another method is hack and squirt--cut small cut in the lower trunk near the ground with a hatchet--apply a herbicide in these cut and it is absorbed by the tree. this is done late summer just before leaf drop. The marks of the cut will be somewhat visible if one looks close. Triclopyr (Garlon 3A) One hack per 3 or 4 inches DBH. Apply 0.5 ml undiluted herbicides or 1 ml of 50% solution in water.
Space the hacks close together.

Pathfinder is ready and a lower % (13%) Where Garlon is to be mixed with water and is a higher %.

Most herbicides have an odor and can be detected that way.

I am not sure this helps and I am not advocating killing a neighbors tree.