For pre emergent herbicides use granular formulations, unless you have specialized spraying equipment, not a three gallon backpack sprayer. For golf courses spraying pre emergents is the most effective solution, but for the average home owner it is labor intensive and probably not as effective as a granular app. For post emergent herbicides use formulations that you can spray. Granular post emergent products have a lot of draw backs. The foliage has to be wet for the product to stick to the plant. The particles also have to be light weight so once the particle sticks to the plant it will stay there without rolling off, so being that the particle is light weight the wind can take the product to places you don't want it to go. Also, you usually can't irrigate or have any rain for twenty four hours after application of a granular post emergent product.

joneboy... thanks for the very informative reply. Based on your feedback I now have a plan! Appreciate it.