re: South LA Lawn

pre-emergent stops seed from germinating, therefore it will prevent weeds that aren't there now from becoming a problem. Should have already put some down, but putting it down right now is better than not. Then, in another couple weeks to a month, treat the weeds that have grown in with post emergent depending on lawn species. ( I have had great success with sethoxydim for grassy weeds such as crabgrass)

Weed and feed is a waste of money because the two applications need to occur at different times of the growing process in order to be effective.