What's the ideal temp to spray 2,4-D for spring weeds in Fescue?

Ijustwantausername

LawnSite Silver Member
Location
Raleigh NC
I tested Trimec on my lawn since it was almost 70 degrees today and because the henbit, clover, chickweed, etc. is a nightmare. I know its still early, so what soil/air temp would you recommend for Fescue? I looked all over the label and it didn't specify a temp. Piedmont of NC.

Thanks.
 

RigglePLC

LawnSite Fanatic
Location
Grand Rapids MI
I don't know. Most experts say to spray phenoxy herbicides when the weed is growing rapidly. Naturally when the weed is young is better. So you may have a separate temp for each weed. And certain factors like inadequate moisture, dormancy or low fertility might slow growth...or perhaps increase your success. And the temperature a few days after spraying could have an effect.

I wish I knew...if you spray when it is cold will you have the same success as if you sprayed when the temperature was warm...only slower?
 

HayBay

LawnSite Senior Member
Location
Ontario
trimec apply when 60-90 degrees f.

You should have no problem with 70 degrees.

As stated you will get best results when spraying while weeds are actively growing.

http://www.pbigordon.com/pdfs/TrimecLawnWeedKiller-SL.pdf

you will need to wait a week or even 2 to see results. If you know what to look for you will see signs of efficacy soon.

If the lawn seems to be outgrowing the weeds after the app, you are in good shape.

Hey Riggles, do you post in the organic section just to get everyone going?
 
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DA Quality Lawn & YS

LawnSite Fanatic
Location
Rochester, MN
Keep in mind lower temps generally slower acting.
Depends also on the mode of action you choose.
 

grassmasterswilson

LawnSite Fanatic
Location
nc
While it has been unseasonalbly warm here and we've had a few warm days you should be ok. More important than day highs is what the night temps will be! If is cold at night it takes longer for the pore of the weed to open up and accept the herbicide.

I'd still give it about 10-14 days to see good results although you should see some wilting if it stays warmer.
 

RigglePLC

LawnSite Fanatic
Location
Grand Rapids MI
I am not so sure about the PPO inhibitor herbicides. Perhaps they work whether it is hot or cold.
However...as I understand it--they DO NEED SUNLIGHT--they won't work at night. Products like Quicksilver, (carfentrazone) or (sulfentrazone).
 

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