According to the product label, you will use 1 teaspoon of Tenacity Herbicide and 3 teaspoons of surfactant per 2 gallons of water. You should expect to need 2-3 applications at 2-3 week intervals to control nimblewill.
Tenacity would be applied as a pre-emergent in spring when soil temperatures are about 55 degrees. This will vary depending on your location, so we advise to reach out to your local extension office for advise on perfect timing in your area. Keep in mind that Tenacity only last about 30 days in the soil when applied as a pre-emergent. So if you are not overseeding your turfgrass, then we recommend selecting a different product such as Barricade 4L.
Tenacity Herbicide is not labeled for coltsfoot. You can see the article below from Washington State where they have done studies on the plant and the recommendations for control. There do not appear to be any herbicides specifically labeled for this weed currently.
Coltsfoot Weed
https://www.nwcb.wa.gov/weeds/european-coltsfoot
Tenacity Herbicide is not labeled for horsetail.
is only labeled to be used in turfgrasses for weed control. If there are no desirable plants in the area where you have rock areas, it should not be an issue to just spot treat the weeds there directly, but usually something like RoundUp QuikPro is more used in this case.
If applying Tenacity Herbicide as a pre-emergent you would want to apply after applying any top soil to other matter to the top of the soil to prevent weeds growing in the new soil
Foliage of treated weeds will cease growth after Tenacity Herbicide application, then turn white (loss of chlorophyll) and death may take up to three weeks. A repeat application is required after two to three weeks for improved postemergence weed control.
We don't recommend using Tenacity Herbicide to get rid of weeds in ornamental plants, it's not labeled for this use. If you have broadleaf weeds, you will need to spot treat with a non-selective herbicide. If you have grassy weeds, you can use a product like the Bonide Grass Beater around listed ornamentals on the label.
Tenacity Herbicide not labeled for zoysiagrass and would not be recommended to apply to it at all.
It depends on what type of turfgrass Tenacity Herbicide was applied to. If the grass is labeled tolerant to the product then it will bounce back as long as it's a healthy lawn. We would recommend to contact your county extension office to identify if it's a disease.
If the Tenacity Herbicide is used on semi-dormant grass, it may harm the turf as you have seen since it is only labeled to be used on fully dormant bermudagrass. You can wait it out to see if the bermuda grows back or you would wait at least 3-4 months to reseed.. The label does not give a specific time frame of reseeding with bermuda when Tenacity is used but since it is shorter-acting than other pre-emergents so as long as the residual of Tenacity is gone, you can reseed/sod.
Tenacity Herbicide only states that it can cause undesired injury to kikuyugrass but it does not give instructions on how to control with Tenacity, which leads us to believe it may only temporarily damage it rather than actually kill it all the way out. Once your new seed has come up and become established to tolerate herbicide use, you could use Hi Yield Turflon Ester to spray over the kikuyugrass to eliminate it from the ryegrass in the lawn.
Per the Hi Yield Turflon Ester Product Label for Control of Kikuyugrass:
Apply Hi-Yield Triclopyr Ester at a rate of 3/8 to 3/4 fluid ounces per 1000 square feet. To improve activity, MSMA herbicide may be tank mixed with the ½ quart per acre rate of Hi-Yield Triclopyr Ester. Three to four additional applications at 4 to 6 week intervals may be required to achieve control of kikuyugrass
Tenacity Herbicide is not labeled to be used on alfalfa or pastures so would be recommended to keep applications at least 10 feet away and avoid any drift/contact from contacting the areas.
Tenacity Herbicide should not be used within 3 feet of desirable trees or ornamentals.
Due to the strength of Tenacity, and the need to not over apply or overlap with it during application to avoid discoloring or excess stress to the desirable turf grass, we do not recommend mixing other post emergent herbicides in the same tank with it unless stated on the label. Tenacity should be applied with a Non Ionic Surfactant and a temporary marking dye like Turf Mark Blue to ensure no overlapping occurs to cause your turf to whiten. We would recommend applying the Triad Select in a separate application. Should you decide to try tank mix the two, we recommend doing a tank mix test first for compatibility, and test a small area to ensure safety to the lawn. Though be aware Tenacity is not labeled to effect bermuda at all.
Foliage of treated weeds cease growth after application, then turn white (loss of chlorophyll) and death may take up to three weeks. A repeat application of Tenacity Herbicide is required after two to three weeks for improved postemergence weed control.
As a pre-emergent, Tenacity will only last about 30 days, so you may re-apply after 30 days if necessary making sure you do not exceed the max application rate per year. However, the product label states “If used for preemergence in established turf, tank mixtures with preemergence herbicides such as Barricade® 65WG Herbicide are recommended for longer residual and broad spectrum weed control.”
