Please reconsider St Augustine. Unless you are growing prairie grasses like buffalo, blue grama, or the wheatgrasses, all the normal turf grasses require roughly the same maintenance (weekly water and mowing with 3x per year fertilizer). Zoysia might be different if you lived in Korea, the Philippines, or Hawaii, but not in the main US. If you don't care whether it looks nice, then you can let it go unwatered without killing it. It will go dormant for the rest of the growing season and come back from dormancy next spring. All during the dormancy it will be subject to uncontrolled weed pressure. The fact that it returns to life after going dormant is what the zoysia proponents refer to as "drought resistant." St Augustine is not drought resistant because it has no drought dormancy state. If you allow St Aug to go bone dry for 3 or 4 weeks, it will die completely and not come back. So, as I said, if you want the grass to look nice, you have to water it.

The best organic fertilizer for YOU is whatever ground up nut, bean, or seed you can find cheap at your local feed store. For me that is alfalfa pellets and corn meal. In South Texas both of those are under $10 this year. For people in the north it is soybean meal. Milorganite is usually available everywhere. I don't use it but other people I trust swear by it. The application rate is 15 to 20 pounds per 1,000 square feet. You can apply any time you want. I try to follow the federal holidays. I start on Washington's Birthday, then Memorial Day, 4th of July, Labor Day, and Thanksgiving. I can remember those dates and they keep the lawn green.

Never till in preparation for grass. Just don't even think about it. Level the area as much as you want at the surface by dragging a piece of chain link fence or a 2x4 around. It might need some weight to actually grab the soil and move it, but that's all you need. Plant the sod right on top of the leveled surface. Then roll the sod down to ensure the bottom of the sod (the roots) are in contact with the underlying soil surface. Roots will not grow through the air to reach the soil.

Why reconsider to st. aug if they require roughly the same maintenance? Empire claims that their zoysia requires a fraction of water, and even if it required the same as st. aug it's softer, smaller bladed and proven the thrive in my area. I'm not really interested in st.augustine. I've been around it long enough to know that I don't like it all that much. If irrigation is required for empire zoysia it's not a huge problem, I just heard that it's drought resistant, and we get a lot of rain April through November. Perhaps I'd only need to water during the drier months, or as needed if we go for over a week without water during the summer (very unlikely).

My area is zone 10a and a subtropical climate. I would prefer for it to look nice (obviously, right?). I have just recently read of people in my area never having their empire zoysia go dormant, or if so, for a very short (under a month) amount of time. I'm guessing these people are watering during the drier months though and have good fert schedules.

Thanks for the info on the ferts, I'll have to check out my local feed store... I've used bulk cottonseed meal (abotu 6-2-2) in the past in different applications. Although 15-20lbs/1000sq.ft might require something nicer on the wallet.

The reason I mentioned tilling is because I have some random clumps of st.aug already, but mostly various weeds and such. I thought that'd make it easier to rip that vegatation apart in preparation for new sod. Would you still recommend the chain link fence or 2x4 with that knowledge?