If you are going to spot spray the brush, 1 oz per gallon works well. Better still is 3/4 oz applied as a spray to wet application. Think about coverage when you are doing this. Also think about drift. I do not like low volume, high concentration sprays of Garlon, Banvel or 2,4-D. You are forced to apply smaller droplets to keep the rate per acre legal. On the other hand, it is easier to apply a low concentration, high volume spray in a manner that minimizes drift. Garlon works better on grape vines, soybeans, vegetables and fruit trees than it does on brush. Superconcentrated low volume spraying does not work well for foliar applications of Garlon. If you want to do that, Arsenal works better. The Garlon will burn off leaves before it translocates into the root system of the brush. Basal sprays formulated in diesel are low volume and very effective on up to 6" caliper brush, but that is very labor intensive for dense stands. On scattered brush, basal sprays are more economical.