Thank you for checking into that, Megatron. That Spectracide product I've talked about works so very well, especially at killing problem grasses in a grass lawn, it's a shame you can't use it. I do understand the issues, though. I use it sparingly and cautiously.

Generally weed and feed products don't work either for feeding or weeding. A liquid weed and feed would be especially poor at feeding due to the low amounts of nitrogen dissolved in the liquid. Grass uses nitrogen in quantities of pounds per 1,000 square feet. Liquids can only supply fractions of an ounce per 1,000 square feet. Liquids can green up grass quickly but only for a short term. You'd have to use it every week or two to keep up with the nitrogen demands of grass. Not only that, but if you use a weed n feed in April you are too early for fertilizer, whereas if you use it in May you are too late for weed control. Timing is always off with weed and feed products. You are far better off to apply an herbicide in April and a fertilizer in May.

Unless someone from CA chimes in, you're going to have to do the research yourself. Please feel free to ask us about the products if you are not 100% confident about them. I like spray type herbicide for two reasons: 1) you can spot spray the weeds and not have to waste product on the entire yard, and 2) you don't have to "contaminate" the entire yard with herbicide like you usually do with dry chemical herbicides in bags.

The herbicides which are safe for St Augustine will definitely mention that on the label. It's kind of a big deal to be safe for St Aug. The 2,4-d types of herbicides will kill St Aug, so watch the labels carefully.