Steven from Frisco, Texas writes
I have henbit, crabgrass, and spurge (a whole lot of all of them); and my St. Augustine is not perfectly healthy right now. I want to get ahead of the weeds, but I don't want to harm my grass, which is still hibernating. I intend to give the grass some good fertilizer, acidify the soil, and get some iron on it as soon as it wakes up, but when it wakes up, the crabgrass and spurge will happily join the already overflowing henbit and choke my St. Augustine to death.
Since you mentioned that your St. Augustine grass is not perfectly healthy right now, we are hesitant to recommend that you apply anything as you may cause more harm to your lawn than good. Herbicide product labels recommend applying products only to healthy lawns, and knowing that St Augustine grass is a sensitive grass we would advise that you contact a local landscaping company or master gardener in your area for the best advice on how to treat while the lawn is not healthy.
Answer last updated on: 03/07/2013