Are esters or amines better on the tough weeds like spurge and oxalis in hot weather? Does it matter whether you are low volume or high volume? Nozzle type? Pressure? Sticker? This needs a test. Myself, 2 years ago, I felt an amine like three-way was slightly better than ester on spurge (85 degrees). I had an elderly lady that had so much spurge she agreed to let me test 4 different products on her front yard, rather than skipping the late summer treatment. I have often heard that the dicamba portion of 3-way is the main component that does the job on spurge.