Are you asking because you're waiting to overseed? If so, November is definitely too late to do so. And I can confirm it does take time and multiple applications to really kill the bentgrass. I think I shared my method in your last post - I pulled the majority of the bentgrass up - I cut it on my mower's lowest setting, then scalped it with a weedwacker. You could also easily pull it up with a garden rake. This exposes a lot of soil. Then apply the Tenacity to take care of whatever you missed. Tenacity does not prevent grass seed from germinating so you can seed immediately. The TTTF I put down Sept 8 after doing that work is already sprouting.

Can anyone tell me what the mixing directions are for bentgrass?
I have the Tenacity and the other thing, but I don't know what the ratios are.

Thanks.

Read your label to know all about mixing, limits, and precautions. There are plenty online accessible labels if you google it.

I'm always nervous applying new chemicals for the first time. I mixed it at the spot treatment rate, applied lighter than the 1 gal/1000sq ft recommendation, and did not use a surfactant. Still, after only 2 applications, it was effective on the bentgrass and my fescue is very much alive.

1/2 TEAspoon per 1 gallon of water.
1 gallon covers 1000 sq ft

Here is a link that might be useful: Tenacity label

Hi guys - resurrecting this one as it has to do with timing of Tenacity application. I'm going to assume that it is too late to use Tenacity to kill Bentgrass patches among a mix of established and newly seeded (this fall) KBG/Rye/Fescue? In eastern Massachusetts - Zone 6a.

I'm done with seeding/overseeding this fall - but wondering when best time to use Tenacity to kill of Bentgrass. I've never used Tenacity, and I assume I will need to kill off the Bentgrass (over several weeks, at least) - then reseed affected areas, which I would prefer to do it next fall, but could entertain doing in the spring.

In short - any advice on when exactly to use Tenacity for bentgrass here.

Thanks!

As long as the target plant is still growing to some extent it will be effective to some extent. If you are still mowing weekly - likely its worth a shot. At the very least it will maybe weaken it a tad, by not allowing it to prep for winter properly.

Will give you a better chance to kill it in the spring. Being that bentgrass is a 'control' vs 'kill' plant for Tenacity... hitting it now and later is always a good call.

I used it a bit late this fall in MN on some invading wild grasses and likely rye - things took a few days longer to whiten up... but they did. So was able to use up my sprayer mix from summer, and maybe put the hurt on some nasties.

Most auxin-based herbicides do depend on growth. Tenacity actually interferes with protein production. While less of that's going on in fall, and energy storage in perennial plants is far greater, it's still happening.

Worst-case, application now will weaken the bent a little bit going into winter. That's definitely not a mistake!

The grass still has some top growth, but very limited (mowing less than 1/week). It's definitely not dormant, though.

Won't I be in danger of weakening the desired grass mix just before setting up for winter?

BoatDrinksq5 - when you say you used on "wild grasses and likely rye..." - I thought Tenacity was "safe" to be used on Perennial Rye...? Just confirming. Maybe you're talking a different variety of rye?

Also - I will continue reading about mixing instructions for Tenacity - I've already read a few differing tips on what to mix with it - but I'll ask this group: Tenacity + what surfactant? Non-ionic surfactant - essential or not? What else? Is just Tenacity + surfactant all that is recommended?

I see these surfactants/sticky products, among others:

Southern Ag Surfactant

Bonide Turbo Spreader

and worth it to get a marker, like this?

Mark It Blue

Just following up per my last comment/question - which surfactant to use with Tenacity liquid?

But also - as I continue researching Tenacity - I'm realizing this is the active ingredient in Scott's Step 1 for Seeding? I always just assumed this was a pre-emergent only in the Starter fertilizer, but if it's mesotrione (tenacity) - is it effective on established weeds/grasses like bent? Basically - is it effective and easier to just apply Step 1 for Seeding in the spring to take care of bent patches? I'm thinking I'd probably have to hit it again a few weeks after initial application - but don't want to fertilize again at that point - so the liquid (Tenacity only) is probably the better solution...

I'd like to order some and perhaps even get an application down before we go completely dormant here in Eastern Mass. Any advice on the surfactant much appreciated!

Stop bending your grass. Problem solved.

Using the starter with weed preventer will not be nearly as effective (if at all) on established grass. Using it as a "weed and feed" is not good...and really "weed and feed" is never a good thing.

Any of those surfacants will work great. Definitely worth the $

Make sure you read the instruction manual for that stuff front to back, maybe twice.

Thanks!!

Well once again resurrecting this thread - now that spring is upon us. To refresh - we're in Eastern Mass, have KBG/P Rye/Fescue mix with bentgrass patches throughout. Also some patches of what I think is Orchardgrass.

Planning to apply Tenacity (which I know is very effective on bent, and marginal on Orchard..)

Question is: when exactly? Yes we've covered that it can be used pretty much anytime - but I'm assuming more effective when grass is actively growing? Which - we seem to be just entering that time. Point is - I'm eager to get it down to start killing, but don't want to waste it if it's too early. The grass is definitely awake now - but not necessarily thriving yet.

And - I'm thinking the answer to this might be obvious - but other than wasting the precious Tenacity, is there a reason why I wouldn't spray the whole yard with it? In a tank sprayer, but I mean try to hit everywhere. I can identify so many patches that it's hard to tell where one patch ends and the desirable grass begins...

Thanks much -

I am in NW NJ and also interested the answer to spring application timing or Tenacity. I still have alot of reseeding and have large areas of bentgrass I am trying to kill. I told our landscape company to hold off on the pre-emergent so i could seed, but not sure when Tenacity would be effective as a pre-emergent and still not compromise seeding. I am considering starting the seed germination process indoors by keeping seed wet so it doesnt take 4 weeks to germinate, as we are still 3 weeks away from ensuring there is no frost. ANY advice would be greatly appreciated!