Originally Posted by wildstarblazer
I would agree with this. Probably better to use something like diquat alone if you need a quick kill to impress a customer or whatever and then come back later with regular Gly.
Diquat is something I use quite often for weed control around desirable plants. Glyphosate is saved for when there is no desirable vegetation nearby. Lawns included. Chemical trimming with even Quickpoo often turns into at least 6 or more inches of dead grass. If I do it with Diquat, there is only about an inch of brown grass. For areas with rank weed growth near ornamentals, I prefer Diquat. If in the name of completely covering a weed, a shrub leaf is contacted, the shrub only gets a spotted leaf.
In Australia, a common practice in AG is to apply glyphosate, wait 7 days, then respray with Paraquat or Diquat. I do intend to try this some day. A "quat" will damage weeds that are either inherently tolerant to glyphosate or are resistant due to selection. I see a lot of glyphosate resistant vegetation, so there is no point in trying to kill it with ever increasing rates.