I keep mine at 2.5 inches and it seems to do really well. I have palmetto St. Augustine in my backyard. At the beginning of the year, I do a small scalp down to about two inches and a light dethatching.

 

I keep mine at 2.5 inches and it seems to do really well. I have palmetto St. Augustine in my backyard. At the beginning of the year, I do a small scalp down to about two inches and a light dethatching.

Right on. I've done 2.5" in the past with my palmetto, but am re-evaluating everything this year.

So I've asked this question in a few places and typically get similar answers "here's what works for me...". I'm wondering if anyone can speak to the actual science behind a specific height?

The closest I've seen is Neil Sperry... he goes on to say "There are those who will tell you that keeping the grass on the tall side improves its summer heat tolerance or winter hardiness, but neither of those is correct. Nor will it improve its ability to survive in periods of drought. Pure and simple, when you keep your lawn low and dense, it's going to be thickest and best.

 

Mowing at 4 hoc here. Last year I mowed at 3.5. the best hoc of cut is the one that holds the best in your lawn. Because everyone going to have an opinion that varies about this.

The same article that Neil done has common Bermuda hoc from 1 1/4- 1 1/2 there's people reel mowing common at sub 1 inch. That should tell ya all you need to know about that

 

I think some of the variance comes from different locations and the particular needs of that place. In my nematode research I'm finding recommendations to have the grass taller - so a place that has a lot of nematode issues may advise higher cutting heights. Or soil differences, humidity differences etc?
Here in Florida the University of Florida advises 3.5-4 inches for St. Augustine - but even that varies by cultivar.

 

I think some of the variance comes from different locations and the particular needs of that place. In my nematode research I'm finding recommendations to have the grass taller - so a place that has a lot of nematode issues may advise higher cutting heights. Or soil differences, humidity differences etc?
Here in Florida the University of Florida advises 3.5-4 inches for St. Augustine - but even that varies by cultivar.

Good point. Around here (Dallas/Ft. Worth) by far the majority are at 2"-2.5".

 

I keep mine at an 1" and it doing great. healthy and spreading. I don't think I could live with it any higher than 1.5

 

I keep mind at 4" just because of the wild Bermuda that grows along with my St. Aug. If I go lower you can really pick it out. visually. I don't have that problem in the back and it is mixed with Zoysia so I have been cutting it at 2.5" with no problems.

 

St. Augustine needs to be kept taller than most warm season grasses, especially if you are in a hot climate with a lot of direct sunlight. 3" would be the bare minimum for a healthy St. Augustine lawn in these conditions but 4-4.5" is ideal. The reason for this should be fairly obvious: St. Augustine spreads only via stolons which are exposed on the surface of the ground. If the stolons do not have adequate shade cover, they will dry out and you will get yellowed/dead areas in high heat areas. Of course, if you have shady areas, you need to keep it higher anyway so the leaves can capture enough light for photosynthesis.

Most people in Texas cut their St. Augustine too low because they (or usually their mowing service) just set the cut height for "normal" southern lawns primarily made of Bermuda grass. Bermuda propagates via rhizomes and secondarily stolons and has much smaller leaves that need to be low to stay dense. Bermuda likes it low, St. Augustine does not.

Mow high.
Protect the stolons and you will have a thick, healthy St. Augustine lawn.

 

Mine is liking 2.75 this year. First time I’ve maintained it that low. It does seem much thicker at this height.

 

Also cultivar dependent. I like my Floratam at 3'', but it requires a cut about every four days or so in the summer.

...and just noticed this post is 4 y/o.

 

Not sure the varietal of st Augustine I have here in DFW, but 3.5” is my current HOC. I’ve experimented at 3”, but that’s typically in early spring.