Applied too much Dithiopyr

Bermuda, St. Augustine, Zoysia, Centipede, Bahia, Paspalum, etc
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soggyturf1
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Joined: April 11th, 2022, 8:41 pm
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Grass Type: St. Augustine
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Applied too much Dithiopyr

Post by soggyturf1 » April 11th, 2022, 9:48 pm

Today I made a big mistake when applying pre-emergent granular herbicide. I applied 2x the requirement for my 5,000 sq foot yard (front and back). Ended up being about 35-36lbs….totally miscalculated. Is my St. Augustine toast?

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MorpheusPA
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Re: Applied too much Dithiopyr

Post by MorpheusPA » April 12th, 2022, 5:26 pm

You should be fine, actually. While the barrier won't last appreciably longer, you've provided a good dinner for the bacteria and other microbes that consume the Dithiopyr.

Dithiopyr is a root pruning pre-M, so green-up may be slower, growth a bit weaker, and so on, for a few weeks until the barrier is consumed a bit. There may be some losses, but I haven't heard that they're extreme until about triple overapplication.

The best way to combat overapplication is, actually, to water it in heavily with 1-2" of water or, if you get lucky, to get a rainfall of that amount within 3-5 days of application.

soggyturf1
Posts: 3
Joined: April 11th, 2022, 8:41 pm
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Grass Type: St. Augustine
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Re: Applied too much Dithiopyr

Post by soggyturf1 » April 13th, 2022, 10:58 pm

Should I wait to apply a second round of it until this fall because I put down so much?

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MorpheusPA
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Re: Applied too much Dithiopyr

Post by MorpheusPA » April 15th, 2022, 10:19 am

I might choose a different pre-emergent this fall due to having overapplied. I'm not sure what that should be on St. Aug, and don't know the grass type well enough to suggest what it should be.

Occasional rotation of pre-emergent types is recommended anyway.

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Dchall_San_Antonio
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Re: Applied too much Dithiopyr

Post by Dchall_San_Antonio » May 1st, 2022, 6:25 pm

Soggy, hmmmm, soggyturf??? Do you have soggy turf? I just replied to your other post, but didn't react to the handle name.

In the other msg I suggested you stop applying herbicides. St Augustine should not need it. Even preemergent should not be needed if the grass is properly maintained. Yes, I know they sell a s-ton of preemergent to St Aug owners, but I've been here for 40 years and never needed it.

If your turf is soggy, ever, you really need to read my other reply. If you continue to have soggy turn, then please post another question about your soggy soil. That would indicate a drainage problem. If not, then it's just a clever handle and I'll move on.

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