Question
I just moved into a new house and wanted to know what type of grass I have. I knew I had St. Augustine, but did not know if the type was Floratam or not and since I was getting weeds I wanted to put down some kind of weed killer on my lawn to try and get rid of them. Well since I could not get a straight answer I went ahead and put down the killer, and boy did it work. So well in fact that not only do I not have any weeds, but my St. Augustine is pretty brown and dead looking as well. I'm pretty darn sure now that I do have a St. Augustine/Floratam lawn but my question is, did I do my lawn in completely or can it be salvaged? It's been a couple of weeks and there are some brown and some greener spots. Anyway does anyone think it'll grow back or what's my next step here? Any help would be greatly appreciated!

Answer
Would the defendant please rise.

Unfortunately, only one post-emergent chemical weed killer can be used on St Augustine Grass, and that's Atrazine.  I guess you used something else.  Once St. Augustine Grass is a rich straw color, it has reached the point of no return; no amount of diluting, no flushing, no antidote will revive it.  D.O.A.  The jury finds you Guilty.

But why would you want to do that to your own Lawn, sir?

I don't mean, Why would you kill the Grass.  I mean, Why would you point compulsively at something called Weedkiller -- KNOWING apparently that IF you have St Augustine, you might wipe it out in a single fell swoop?  KNOWING that an ingredient in many weed and feed products -- the infamous 2,4-D -- kills St. Augustine Grass?

Let's make some Lemonade.

Let's LEARN at least a little from this mistake -- besides the fact that you HAD St Augustine, and still HAVE a few blades that have survived your slash/burn technique.

Lesson One: All Weeds are not created equal.  Do you read me?  Even if this herbicidal solution HAD spared your St Augustine, it is very unlikely that it would have solved your weeds problem.  Example: Weed B Gon is a 2,4-D mixture guaranteed to wipe out plantains, wild garlic, dandelions AND EVEN your St Augustine Grass -- but it DOES NOT WORK on common chickweed, purple deadnettle, ground ivy, white clover, violets, or henbit.

The Scotts Corp would like you to believe there is a simple answer to everything, and the simple answer is always available in a bag with the Scotts logo.  Turfgrass chemicals often damage -- and infrequently destroy, as you have learned -- the Lawns they are meant to treat.  'Weed 'N' Feed almost always entails applying one of the ingredients at the wrong time -- you can't effectively 'weed' at the same time you 'feed'.  Unlike other grasses, Lawns of Centipede, Zoysia and St. Augustine should be fertilized during or after green-up.  On a St Augustine Lawn, application of chemical Weed Killers is scheduled before St Augustine greens up in the spring.

I tell you, if hospitals and law firms worked like this, we'd all be dead or in jail.  Broadleaf, Perennials, Summer Annuals, Winter Annuals, Grasses -- Weeds are not a single kind of plant.    Weed Killers are not a single kind of answer.  

Lesson Two: The most effective, least expensive, best solution to Weed control is NOT to buy all the Weed Killers you can buy without killing your Grass.  Weed Killer is not cheap; it must be applied yearly.  And it comes with side effects.  It alters soil chemistry in a very short time, turning the soil into a barren base of dirt.  With microorganisms and arthropods virtually eliminated, there is no way to obtain nutrients other than doses out of more bags of chemicals, and no way to contain disease bacteria and fungi.  20 years ago, we did not know much about soil chemistry.  Today we have much better ways to control Weeds and Disease.  Of course, marketers also have better ways to convince the right people that the old system is the friendly, safe and effective, so you have to look past the smiley faces of the actors and commercial sets, and listen to the Long Island Gardener.

So you were considering you might be growing Floratam?  'Floratam' St. Augustine grass was introduced in 1972 at Florida and Texas Agricultural Experiment Stations.  Researchers were looking to develop a SAD Virus and Chinchbug resistant Lawngrass.  Floratam also turned out to be Brown Patch Fungus resistant and exceedingly drought-tolerant, as well (but not cold tolerant).  

One of the BEST ways to eliminate weeds is to avoid getting them in the first place.  This may seem obvious, but if so, why didn't you do that?  Just keeping Weeds from going to seed is a major Weed eliminator.  A single Annual Bluegrass plant will generate a whopping 2,000 weed seeds per plant.  Crabgrass will prepare 53,000 seeds per plant.  Pigweed, a dizzying monster-sized 200,000 seeds OR MORE per Pigweed.  That's what you avoid every time you eliminate one of those weeds.  This, my friend, is the progressive new way to delete weeds from your Lawn.

For additional reference, I refer you to the Texas A&M Aggie Horticultural Website, which posts a handy little cheat sheet, 'Weed Control in St Augustine Grass' (http://aggie-horticulture.tamu.edu/PLANTanswers/turf/turfweed.html).  I disagree with the way they promote sweeping use of pesticides even while pushing the environmental value of a lawn.  But it's entertaining, and some of it is helpful.

The next step?

You mean, when you are out on probation?

See how much Grass survives.  Some yellowed blades may recover.  You've already waited a few weeks at this point, so you probably have a pretty good idea of how much is still there.  Make a point of taking better care of the Weeds problem on your next St Augustine Lawn.

The simple fact is, a St Augustine lawn should NOT have Weeds.  Frequent watering and the mowing at the wrong height will encourage Weeds.

Why?

You have to take GOOD CARE OF YOUR WEED SEEDS for them to germinate.  Skip a few days, let the sun bake, let the soil dry to the St Augustine breakpoint, and those Seeds don't have a chance.  If you can water weekly, instead of daily, and soak your soil (which should be able to hold a substantial amount of moisture if you have good soil), you won't get new Weeds in your new St Augustine Lawn.

Of course, there are still going to be Weeds that make it anyway.  Which is why it's such a good idea to mow properly.  I know people who let their St Augustine Lawns reach 5 or 6 inches before they mow it down to 4 inches.  Mow your St Augustine nice and high.  Let it smother any Weeds that think they stand a chance at prospering on YOUR Lawn.  Send them a message: Weeds, be gone!  

But Jacob, turning your blessed home into a Superfund Site is not the answer to your Weeds Problem.  It's time to grow Grass the 21st Century Way.  The Earth is Round.

Any more questions, I'm here.  Thanks for writing.  Keep me posted.  We'll delay sentencing until after your new lawn is in.