Howdy, All,

I had three quarters of my St Augustine lawn replaced in December due to some thing (insects or fungus) killing it.

It looks great! Except that I'm seeing dollar weed and bermuda grass in the one quarter of the original grass and in the flower beds.

How do I kill them without killing my new St Augustine lawn.

Thanks!

Atrizine
Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz Specialty Herbicide, Light Tan
https://a.co/d/9w5NEYf

Fixed the same problem for me. Buy a pump sprayer and follow the correct dosing.

Dollar weed likes moist conditions so water less frequently and improve drainage in the infested area (aeration helps too). Some chemicals will kill it like mentioned but you need to change the conditions as well.

Bermuda is next to impossible to kill without killing rest of the grass.

Hopefully mowing higher, watering less frequently but deeper, etc. helps the good grass choke out the other.

Most liquid spray herbicides that are safe for St Augustine (most are) will take care of the Dollar weed.

Now the Bermuda.......good luck. Anything that hurts the Bermuda will hurt the St. Augustine.

Got another question for you:

3/4 of my lawn was laid in December 2024. The atrazine bottle has instructions for 'established lawns'.

How old does a lawn have to be to be considered 'established'?

Regarding the moist conditions: I don't water the lawn at all now. The area where the dollar weed and bermuda is gets full sun. The mower is set at its highest setting.

The bermuda in the front yard isn't that bad to let it take over the St Augustine, yet.

I have been able to control all weeds pretty successfully but for wild bermuda. I had to kill/till/fill an entire area of my lawn to get it back, at the very least, under control. I've got another area I'm trying a different approach with - trying to get the ST A to simply overtake it. Slowly. It sucks.

It's a pain but you could pull the Bermuda out by hand and mow really high so the st augestine crowds it out. It could take a while though

Atrazine will stunt Bermuda but it is hard on trees/shrubs

The dollar weed you see now is just left over from previous season and will take some time. It has long, underground roots that are very resistant compared to other broadleaf weeds. Keep treating with chemicals and improving conditions and it will work over time.

Recognition with Fusilade II will kill bermuda while being safe for St. Augustine.

Ethofumisate (POAConstrictor, Prograss) combined with Atrazine can also be used for control of Bermuda grass in St Augustine. Just don't apply Atrazine in the drip line of desirable trees and shrubs.

Some years ago, a former co-worker of mine had moved to SW Houston area from somewhere back east. We were talking lawns one day and he mentioned he had seeded his lawn with Bermuda over the existing weak St Augustine and it was coming out really well. I was like "Why in the Hell would you that instead of working to improve the St Augustine?". He was kind of taken aback and said "Well, that's what we had before and I like it". OK, good luck with that! A few weeks later, he's not happy with how his lawn looks in comparison with others in the neighborhood and asks me how he can gets rid of the Bermuda without killing the St Augustine and I told him I just didn't know. He starts researching the issue and found a paper published by a professor at Clemson on the use of Ethofumisate and Atrazine for that purpose. He ended up contacting the professor who provided him with additional info, including mixing/application rates and so forth. A year later he had a mostly St Augustine lawn and was pretty happy with it.

https://thelawncarenut.com/blogs/news/how-to-get-rid-of-bermuda-grass-in-st-augustine-lawns?srsltid=AfmBOoo_-Ef60S5i509tOJ78kACxdywhvgVQyCa0f8TAh7zMnXq4oIOG

.85 grams Recognition,.55 oz Fusilade II, 1 oz surfactant / 1,000 sq ft

reddog90 said:

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https://thelawncarenut.com/blogs/news/how-to-get-rid-of-bermuda-grass-in-st-augustine-lawns?srsltid=AfmBOoo_-Ef60S5i509tOJ78kACxdywhvgVQyCa0f8TAh7zMnXq4oIOG

.85 grams Recognition,.55 oz Fusilade II, 1 oz surfactant / 1,000 sq ft

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Good stuff!