Tenacity Herbicide can be used on a lawn that 2,4 d or other herbicides have been applied to safely as long as you follow label instructions and apply it evenly. Tenacity will only last about 30 days as a pre emergent compared to other pre emergents on the market that will last 3-4 months. Tenacity is mostly used as a pre emergent in the spring or fall when customers are over seeding their lawns with a cool season grass to fill in bare spots, as its one of the only products that can be used at this time without harming the seed. If you are not seeding, you may want to consider a longer lasting pre emergent or one that covers a wider range of weeds than the Tenacity does, like the Dimension 2EW or Pendulum 2G for instance. If using Tenacity as a pre for crabgrass, you want to put it down at or just prior to your soil temperatures reaching 55 degrees in order to be effective. If soil temps have already progressed past 55 degrees your pre emergent will not do much to stop the weeds.
If the Tenacity Herbicide application had enough time to completely dry before the temperatures spiked to 93 degrres, there shouldn’t be any issues. It is recommended to apply Tenacity when temperatures are between 65 to 85 degrees so early morning or late evening applications may work best if temperatures above 85 degrees during the day are expected. If any yellowing or discoloration occurs, the turf should recover after a couple weeks.
As stated on the product label of Tenacity, this product should be applied when there is no rain in the forecast for at least 48 hours. "If rainfall (0.15 inches) has not occurred within 10 days after preemergence application, activate with 0.15 inches of irrigation." This product can be applied to established, tolerable turf types.
Please be sure to review the product label for more information and complete application instructions.
It would be best to wait to apply Tenacity Herbicide until the grass has completely dried before the application. Be sure to mix in a Non Ionic Surfactant when doing post emergent applications.
Tenacity Herbicide is best applied 2 weeks before planting/seeding a lawn or wait at least 2-3 weeks after seeding to apply. When pre-germinating and planting in the area we would recommend waiting at least 4 weeks to apply so it is established.
Tenacity Herbicide is not labeled for zoysiagrass.
No, Tenacity Herbicide cannot be used on residential St Augustine lawns. It is only for use on St Augustine grown for sod as listed on the product label.
Some folks do use food coloring/dye to mark where Tenacity Herbicide has been applied. How much you use depends on the depth of color you want. We apologize but cannot advise on the exact amount.
No, Tenacity Herbicide is not labeled for application to bahia.
Tenacity Herbicide does not list English ivy on the product label, but it is labeled to kill ground ivy so we would not recommend applying it to any desirable ivy.
Products that have been mixed with water must be used within 24 hours after mixing. Please contact your Local Sanitation Dept for guidelines in your area on disposal of unused Tenacity Herbicide .
Spray foliage of target weeds with Tenacity Herbicide until wet but not until the point of runoff.
Tenacity Herbicide is not labeled for use on a dichondra lawn, and it is not labeled for spurge. Dichondra lawns are considered a type of ground cover, and many herbicides may prevent this type of lawn from growing. Please contact your local cooperative extension office Master Gardener for assistance on products that will take care of the weeds in your lawn without causing harm. Please let us know if they suggest a product, and we will certainly make an effort to locate it for you.
Tenacity is not labeled to control undesirable ornamental plants, although it may harm them if sprayed accidentally. You will need to remove physically all the parts of the iris - including the rhizomes in the soil – in order to prevent these plants from regrowing the following year. You can use a glyphosate product such as RoundUp QuikPro to kill the above ground plants, but you will need to remove the rhizomes after spraying. This article has easy-to-follow directions on this treatment, which is best done in the fall.
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.
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
If you are applying it as a post-emergent herbicide, then Tenacity Herbicide should be applied when there is no rain in the forecast for 24 hours. If you are using it as a pre-emergent, then it would need to be watered in and could be applied before rain as long as there is not so much rain that the application would just get washed away.
If you are applying Tenacity Herbicide for a crabgrass pre-emergent, then you would apply in late early spring before soil temperatures reach about 55 degrees. Keep in mind that if you are not overseeding in the spring, you usually want to use a different pre-emergent with longer soil residual or add another one for longer and more complete weed prevention.
We have more information in our Crabgrass Pre-Emergent Guide here.
If you notice on Tenacity Herbicide’s product label, there are two different rates for application. There is a broadcast rate- meaning spraying the entire surface of the property, and a spot treatment rate. Spot treatments are often a different use application than for broadcast, especially for a unique product such as Tenacity. The main broadcast applications being made are going to be used as a pre emergent. The broadcast applications are not best for post emergent control, and the manufacturer recommends spot treating when going after existing weeds. Controlling an existing weed and preventing weeds from seed germination will be two different application rates, and one uses a surfactant during treatment (post emergent) and one does not (pre emergent).
Also, you would only be calculating per gallon of water if you are doing a post emergent spot treatment. Pre emergent applications will have varying water volumes based on a customers turf type, density, application equipment, and application speed. This means you are focusing on an amount of chemical per square footage/acreage, and not per gallon. The water is merely the carrier to get the small amount of chemical distributed evenly across the correct amount of space to yield the intended results from the product. For many, a pre emergent application will vary from 1 gallon to 3 gallons of water per 1000 sq/ft.
If you do not know how much water you will cover 1000 sq/ft or an acre with, you can calibrate your equipment by using only water first, and mark off a 1000 sq/ft section of yard. Walk as if you are applying it with chemical in a way that seems like sufficient coverage for your lawns needs. When finished, look to see how many gallons of solution you used, and then you can move forward with determining how you need to mix it based on this information for your 4 gallon tank.
You should not mow within 2 days before or after an application of Tenacity Herbicide or any other herbicides.
