Originally Posted by greendoctor
Simazine + MSMA will take down most grassy weeds better than either one by itself. A case of 2+2=7. I can kill goosegrass, crabgrass, crowfoot, and smutgrass, all of those are major problems here. This is especially valuable on zoysia, because the normal Sencor + MSMA tank mix will kill zoysia. Bermuda grass tolerates the MSMA + simazine much better as well. There is much less yellowing and dieback. Most MSMA on the market is 6 lb per gallon. So I am usually doing 3 lb/A. I will really miss MSMA when the EPA pulls it. Drive and Dismiss are illegal in Hawaii, so my options are limited. There is no real winter here, so preemergents will only stop future generations of weeds. Also, don't know if it a soil or climate issue, but the grasses here do not tolerate herbicides such as Dimension, Pre-M or Barricade very well. The root pruning effect damages the lawn and actually opens up the turf to weed invasion.
I don't know much about the growing zone in Hawaii, but there is never a time (except an oddball spotspray) when I would mix Simazine and MSMA. In the South, they are just not needed at the same time, for the most part. Spraying MSMA in the fall, winter, and spring, when the Simazine is being applied, is a waste of time.