Tenacity Herbicide is only labeled to be used on Bermuda when it is dormant, otherwise it can be sensitive to applications and could harm it. Since Tenacity Herbicide can be used only on fully dormant Bermudagrass, there is not a time when you would be overseeding and using Tenacity at the same time. You would overseed with Bermuda when the turf is actively growing in spring or summer, if needed at all. So if you applied Tenacity on dormant Bermuda, then it would be long gone by the time the turf is completely green and any seeding would be done. If you would like to tell us more about the weeds you are targeting, then we can recommend alternate products for your needs.
Tenacity Herbicide should be applied on a non-windy day as directed on the label.
To control nimblewill, start applying Tenacity in the spring (late-April) with a nonionic surfactant. You will need to make two or three applications 2-3 weeks apart. You will use it at the 5 oz per acre rate per the label. The product does have a yearly maximum use rate, and the label states "do not apply more than 16 oz of Tenacity per acre per year or per crop (equivalent to a maximum of 0.50 lb of mesotrione per acre per year).You can also apply Tenacity in late summer and fall, but you should initiate them by August for best results. Good cultural practices on your lawn can help reduce its ability of coming back as well.
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 can be applied at the same time as seeding (unless grass is more than 20% stand of fine fescue). If application cannot be done within 7 days of seeding you would need to wait a minimum of 30 days, or until the seed has emerged and been mowed at least twice before applying to the lawn.
According to the Tenacity product label, you will need to mix 1 tsp of product + 3 tsp surfactant with 2 gallons of water for spot treatments applied at a rate of 1 gallon per 1,000 sq ft. It is advised to use a dye like Turf Mark Blue with it so you can make sure to not overlap if you plan to do a broadcast application on the property. Repeat applications can be done after two to three weeks for continued post emergent weed control.
Ideally, you would not want to put a fertilizer down when the lawn is getting ready to go dormant. If anything, an application could be made now in early October as your last treatment for the year. Tenacity would not be effective on lespedeza (japanese clover) at all as its not labeled for it. Southern Ag Atrazine is labeled for lespedeza and is safe for use on Centipede lawns if used as directed. Another option is Fertilome Weed Free Zone.
Tenacity Herbicide is not labeled for clump fescue, and it is safe for tall fescue.
Tenacity Herbicide cannot be used on home lawns that have St Augustine. It is only for use on St Augustine in sod farms.
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.
You would want to wait 24 hours after the application of 1 product before applying the second product.
