[DAVES]

Truth I am writing this to procrastinate doing mine.
Endless debate. In the end no matter what you do you will have weeds.
Preen and the same chemical by other brandnames. It only kills seeds and is not 100% effective. Several weeds, including grass from your lawn spread by runners. That is true of both empire zoyzia and st augustine. Preen will not stop this. Roundup, glycophsate, also sold under different brands besides roundup-currently being sued by the way.

Easiest, quickest and you do not need to wait a week or two for the weeds to die and then you need to pick them out anyway is to simply pull them out. Far easier to do if you do not have gravel and or landscape fabric either of which prevents the use of traditional and effective tools. Aside-if you watch the pros, the people who do the Villages landscaping, you will see they do not use landscape fabric or gravel, they use pine straw..