Since the product label does not indicate a time frame on when Grass Out Max (Clethodim Herbicide)
According to the product label
GrassOut Max is not for use on turfgrass so should not be applied to lawns.
Grass Out Max in theory would likely harm St Augustine grass since it targets similar grasses such as bermuda. However if the herbicide is not listing it as a control plant, then we couldn't say that it would actually be effective.
Yes, Grass Out Max (Clethodim Herbicide) can be applied over ornamental plants in nurseries to control crabgrass and other grassy weeds but will not
We do apologize if any misinformation you may have read in past Q&A