# Timing Herbicide Apps to Mowing?



## XLT_66 (Jul 17, 2018)

Hey guys. New to this level of lawn care.

I'm mowing about every three to four days, around an inch to inch and a quarter HOC.

I've put out milorganite earlier this week, have watered once (about 1/2") and have never sprayed any herbicides before. I've got the Chapin 20V and just got an idea for my pace to spray about a gallon per 1000 sq. ft.

I've got Prodiamine, Celsius, and Certainty. I've got a few areas that have a fair shake of crab grass and then I've got a sprinkling of a variety of other weeds around the yard I can't identify.

My question is, if I'm spraying these chemicals, should I do it after I mow? Is it okay to spray it a day before mowing? What's the rule of thumb here?

Thanks!


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## Spammage (Apr 30, 2017)

Check the labels as they will normally tell you. I know Certainty says to wait two days after mowing and an additional two days before mowing again. If the label doesn't state otherwise, this is probably a safe guide for others as well.


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## reidgarner (Jun 18, 2018)

Pre-m like Prodiamine and dithiopyr need to be watered in after application for best results. I wouldn't mow until after it has been watered in. Mowing before probably has no effect.

Post-m usually needs to sit on the leaf for a couple days to absorb. You also don't want to mow right before application because the weeds will be recovering from the mowing and won't absorb the chemical as readily. That's why most post-m labels reccommend no mowing 2 days before and after.

When in doubt, always defer to the label of what you are applying.


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## Movingshrub (Jun 12, 2017)

During the summer its challenging to mow every five days on Bermuda depending on the HOC. I tend to spray whenever the weather and my schedule allows, mowing schedule comes second. If it it's crabgrass, usually enough plant left to spray after mowing. If it's a sedge, I try to spray a day or two before mowing if possible.


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