Winter in Florida can be interesting, and this year is no different. Where I live in Bradenton, we have gone from highs in the 90s just 2 weeks ago to the 70s, and today, we just got a big rainstorm and had 16 straight hours of high humidity, which is pretty rare for this time of year. Overnight lows got down into the 40s for a couple of nights, hovered in the 50s for 10 days, and now are back up to the 60s.

All of this is bringing some interesting reactions in the lawns, and so today, I’m going to show you exactly what I see in my neighborhood so you can compare and see if any of these conditions are the same for you.

But before we get there, download the Florida winter guide and pay attention to this map:

If you are on the north end of that map, your lawn is probably all brown and dormant right now, so really, your job is to wait it out until the spring when the days get longer and the lawn starts to grow and green up again, usually sometime in early March. Usually sometime in early March. However, if you have not applied pre-emergent Prodiamine (it stops weeds), you do want to do that right now. It’s ok to apply pre-emergent to a dormant lawn - get prodiamine here.

For everyone else who lives around I4 and south, your lawn is probably still in some state of “green,” and you are likely still having to mow at least every 10-12 days. The further south you are, say Ft Myers on the West or West Palm Beach on the East, your lawn is probably still green and growing with you mowing every week just like normal.

For all of you (and me, too, here in Bradenton), here is some of what you may be seeing:

Grass with Purple Tips

This is my Floratam St Augustine grass and it was pretty tall (unmowed) on the night when it got down into the low 40s and some of the tips got a little cold strained. That is what it means when it’s cold out and your lawn turns reddish-purple - that is cold stress. No long-term damage there - just cut the lawn and cut the damaged tips off to reveal the green beneath.

Tip: Those low 40s temps made some of the lawns in my neighborhood go semi-dormant. My lawn right now is still dark green and I’ve already cut off the red damaged tips - but the rest of the lawns in my neighborhood have gone semi-dormant. What is the difference?

My Lawn - I keep it irrigated with 1” of water per week. I’m watering 2-3x per week, ½” each time. This keeps the lawn hydrated, which helps it resist going dormant when it gets cold out. Additionally, I’ve kept my lawn vigorous with Nitrogen. A lawn that is growing is burning its internal furnace, which keeps it from going dormant. Unlike lawns that are Nitrogen-starved right now and therefore very slow anyway, the cold weather just puts them right out!

So the tip with this is to keep your lawn pushed with fertilizer (Stress Blend) during winter and also keep it irrigated. Here’s the thing to know: if you are reading this and you live in Tampa or Orlando and your lawn is in that “semi-dormant” state from the cold and lack of water or fertilizer - you can get it turned around starting now but it’s going to go SLOW so be patient. Apply your Stress Blend, water it in, and start watering the lawn 2-3x per week keeping the waterings separated by 24-48 hours (let the soil dry out between). Water in the mornings.

Tropical Signalgrass Does Not Like The Cold

One good thing that colder temps brought is the end of this season’s crop of tropical signalgrass. Further south, where it doesn’t get cold, the signalgrass lives year-round, but here in Bradenton, when it gets into the low 40s, signalgrass is an annual, and it drops seeds and dies from that cold. The thing about that is it sometimes looks like disease in the lawn. This is my neighbor’s lawn up the street. If you only saw this picture and I gave you no other context, you could easily think these dead patches are large patch fungus in this St Augustine lawn.

The way you know it’s tropical signalgrass is you get down and look at it up close. Some of you may not have even known it was in your lawn and then the cold killed it and left it looking like this picture! Here is a video showing tropical signalgrass when it’s growing (in my lawn).

Here is a picture of the tropical signalgrass dead, but up close. Can you see the seed heads in there? That is a telltale sign..

Either way, this is not disease - always get down lot and close in the lawn and look. Now, one thing that is also important is preventing future outbreaks. Prodiamine pre-emergent does quite well against tropical signalgrass (future outbreaks) but you have to keep it down pretty much year-round. You can apply an application right now if you have not already and then you’ll be prompted by the Yard Mastery app to apply again sometime in later January or Feb. (the app is shut down for the season, will be restarted and new programs calculated in early Jan).

Large Patch Disease

Now, we are seeing quite a bit of large patch disease breaking out. It’s normal so do not be too concerned about it if you have not treated for it yet. In fact, we are at the point where it’s probably too late for many of you to apply fungicides for it.


If your lawn is semi-dormant and you are seeing outbreaks, I recommend just letting the lawn go fully dormant and wait it out - just let the disease starve out from lack of everything. Stop watering, stop fertilizing, and just let the disease stop. You can resume lawn treatments in late winter or early spring when the days are longer and the grass wants to grow again.

Here is a video showing a professional product I used and here is a video showing store bought options you can use.

Again, if your lawn is dormant or semi-dormant, do not apply. If your lawn is still green and you are mowing at least every 10-12 days, apply fungicides, continue fertilizing with Stress Blend, keep watering 2-3x per week in the mornings, and hope for the best!

I’ll see you in the lawn!
Al