Tenacity herbicide

We had a discussion going off topic in the “Combatting Brown Rot” thread Combatting brown rot - #148 by speedster1 about using Tenacity herbicide. @Speedster1 @mamuang

I bought some this spring and just got around to using it last week.

I spot sprayed on July 1 with an older Hi-Yield spreader-sticker. Weeds started showing effects about Thursday last week. Tenacity inhibits carotenoid synthesis, and carotenoids protect chlorophyll from light damage. As a result the new leaves on the weeds are turning white due to photo-bleaching of the chlorophyll. Perhaps not quite as satisfying as 2,4-D twisting, but still sort of satisfying.

So far it looks like it is doing a good job on the crabgrass in a neglected and poorly mulched weed, err flower, bed. Dandelions also appear to be taking a beating in the yard. Plantain appears totally un-phased. Some clover is showing whitening signs, but other patches seem OK.

I am also seeing bleaching of my bluegrass. I hope it doesn’t get fried, but hopefully this much needed 1.3" of rain will help. The KBG bleaching is on the label, so not unexpected.


I can certainly vouch for its effectiveness. Although admittedly it makes my lawn look horrible with the white patches. But at least I know that the Nimbleweed is dead and I can power seed in the fall.

Its worked well on Annual Bluegrass (the weed) and some assorted weed grasses I’ve not identified.

I like that picture upside down. Not the weeds but the background with the hills and swales. It looks like a roof…!!

Haha. The picture shows up perfectly fine on my cell phone. For some reason the forum software is still massing with my pictures.

Yes it easily wipes out crabgrass. Bit I’m not wasting it on crabgrass when much cheaper herbicides easily handle crabgrass. I’m saving the teenacity for those grasses that have no other way to kill accept for glyphosate.

This is another picture of how it works selectively. I’m not sure what this grass is but I know its hard to selectively kill. It may be the bad tall fescue. My base grass is KBB and turf type rescue mixed with lots of clover. But without a pre emergent weird grasses have taken over. You can see the green color has been removed from the grass blades.

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Wish you could use it on ground ivy/ creeping charlie and take pictures to show us

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Tenacity is off patent and generics are dirt cheap if you have an applicator’s license.

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I don’t have a license and I wasn’t aware it is off patent. Why can I purchase Tenacity without a license but not the generic?

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If it is not on your state’s restricted use permit list you can at an ag retailer, but they may want to have a license number for their records. Varies state by state on .rules.
Just one example:

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