Killing St. Augustine in Palisades zoysia

Killing St. Augustine in Palisades zoysia

clbammel – posted 11 May 2006 11:30

I live in Brenham, TX, between Houston and Austin. I made the decision to go with Palisades zoysia for all the reasons posted on the other threads. There was a small patch of St. Augustine on the side of the yard when I bought the place. The rest of the yard had nothing but weeds and grassburrs. The zoysia is now establishing well, but all of a sudden the St. Augustine from the side yard has started encroaching on the zoysia like gangbusters.

Is there any way to kill the St. Augustine that has invaded my zoysia without killing the zoysia at the same time?


TexanOne – posted 06 June 2006 02:09

There are a few things you can do to slow down or stop the St Augustine in Zoysia, depending on how radical you want to get. I’ve listed the choices from least to most aggressive:

1: Get commercial-grade MSMA herbicide and apply frequently and heavily at maximum recommeded rates to the SA. Depending on the SA variety you have in your yard, the effectiveness will range from “somewhat controlled” to “useless”.

2: Apply “Drive 75DF” herbicide to the SA. Drive is sold at Ag-outlets (you can’t buy it at Lowe’s or Home Depot), and it isn’t cheap either. A 1-pound container of Drive will cost over $100. Drive is very effective against SA, but it does not kill SA outright – it just simply slows it way down.

3: If the SA is confined to a small area, you will much better off using Glysphosphate (Roundup) and killing it before it completely takes over. Of course, this will kill the Zoysia too, but SA is FAR more aggressive than Zoysia.

Also, if you are in a residential area with neighboring yards of SA, you are really wasting your time trying to stop the SA. You may have a chance with maintaining Zoysia if you install a physical barrier to stop the SA from penatrating into your yard – otherwise, you’re sunk

Before I say anything else, I must tell you that I am a big fan of Zoysiagrass, and much prefer Zoysia over SA. However, there are some realities about Zoysiagrass..

I’m in West Texas and you are fighting the same battle I did from 1999 – 2005. I had a beautiful stand of Zenith/Palisades Zoysia that was completely overrun by SA and there was virtually nothing I could do about it. I finally gave up and allowed the SA to take over, and I had a concrete curb barrier installed before I installed the Zoysia. Honestly, the SA grass that took over looks much better than the Zoysia anyway.

I don’t know about the rest of the country, but in hot, arid West Texas, SA is superior to Zoysia in just about every category except cold tolerance. SA uses less water, has better hot/arid performance, resists weeds better, and is far more aggressive than ANY Zoysia in spread rates.

If you want to experiment a little – stop watering the Zoysia / St Augustine mix and watch which turfgrass species wins in drought resistance/tolerance/recovery.

Hope this info helps you decide what to do…

Asian Cajun – posted 06 June 2006 11:14

The best and safest way without damaging your zoysia grass is to pull it out by hand, try to get all the roots out using a V-shape fork like tool. They are fairly easy to pull compare to bermuda grass but overall, it takes time, if the soil is wet, it does help alot too. Good luck and may the force be with you. PS, I just hope it only a small area. I did have crab grass all over my empire zoysia lawn last year but I keep on pulling it out by hand and now, all are gone. Still fighing the bermuda grass dough. Hope this help.

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