+1 for G.R.I.T.S recomendations. Especially the Lesco 8-2-12.

Be aware the new areas have a sand base with less than 6" clay + soil and then sod on top so make sure you're not getting a lot run-off with longer watering cycles.

You may need to break watering up into several shorter cycles with time inbetween to let the water soak in.

The subcontractor that T&D used to re sod our lawn after a pool build told me they will only use Floratam sod. It is a St. Augustine hybrid jointly developed by the university’s of Florida and Texas A&M, hence the name Floratam.

Seed?
 

I wouldn’t put any seeding down. It makes for some strange and ugly looking lawns. The colors likely won’t match, and most grass doesn’t take the heat like St. Augustine.

CRABGRASS KILLER will
wipe out your lawn... You are not up North ..

Preen offers a crabgrass killer for St. Augustine lawns. I order it from Home Depot as it is not carried in the stores. Does a good job.
https://www.homedepot.com/p/Preen-15...4064/308249265

Technically, St Augustine is a type of crabgrass, so beware when needing a weed killer. The only weed killer I use is Atrazine which is made for only St Augustine lawns. You mix a batch up in a half gallon sprayer and before you mow, go around and spot spray any weeds in your grass. It kills the weeds but not your St Augustine lawn. I buy it on Amazon.

You got some good info here. Especially the link from the agricultural office at the Univ of FL.

Read that twice to fully understand what they are saying.

Key points to make grass grow are water, food (fertilizer), light (sun) and mowing height. Either too much or too little of those and you will have issues.

If you’re in a new area and want a good lawn, you really need to care for it yourself. Lawn care companies can only put down 2 lbs of nitrogen by law. In the poor soil we have, in a new area, your grass could use 3-4 lbs to thrive. Sandy soil leaches nutrients quickly, a liquid fertilizer has no chance of staying in the soil a long time. Pellets are the way to go. Using a low nitrogen fertilizer like Millorganite in between “big” feedings will help your lawn stay healthy.

Mowing height is critical for success, low cut heights open up the area for weeds to take hold. In thick turf, they (the weed) will be challenged to put down a good root system. I do a weekly walk about to either hand pull or spray the weeds during the growing season.

While you’re doing your research on line for turf, start looking at irrigation system maintenance. It’s inevitable that you will need to raise a head or make an adjustment to it sooner or later, if not already. I’d look at You Tube for some tutorials.

If you’re interested in water conservation, evaluate your irrigation controller to see if it fits your needs. We have a newer “Hunter” controller. I bought the module that connects it to WiFi so that I can control it from my phone. I monitor the weather and can shut it off remotely based on rainfall. It’s really convenient. Lots of info on this forum and You Tube on that option. There are other irrigation controllers available that offer a more “hand off approach” to water conservation, but what I have works for me at this point.

In our area they installed Scott's ProVista St Augustine. It supposedly grows slower than Floratam but the main benefit is that you can use glyphosate to kill weeds and it won't hurt the grass.

Our house backs up to a preserve and has a common area on one side so I get a whole variety of different weeds. The hardest ones to kill are torpedo grass and common bermuda which were a struggle. I thought I had Floratam but talking to a Greensmith tech who told me that I has ProVista. Once I found out I started using glyphosate once every couple months and it kills everything but the ProVista.

When we had our pool built I specified that they use provista.

THERE IS NO ST AUGUSTINE SEED!!!

Take care of your soil's poor pH 1st, before doing anything, or you are wasting your time,