We recommend that you mix Tenacity Herbicide with a non-ionic surfactant for the most effectiveness.
Pre-Emergents typically should be applied in the spring before ground temperatures reach 55 degrees and again in late summer/early fall. For more specific recommendations based on the current climate of your region we would recommend contacting your loacal Master Gardener. Please click on the link below and select the region in which you reside to find the contact information for your local Cooperative Extension Program office.
http://ag.umass.edu/umass-extension-your-community
There should be no issues applying Tenacity around the same time as a feritlizer as long the label on the fertilizer does not state that it cannot be used with herbicides.
Tenacity is an effective herbicide for weed control prior to or during seeding of certain turfgrasses during turf renovation. Please see section on use in New Seedings in the Product Label for complete instructions and limitations for your specific turf type.
If you plan on aerating it is best to aerate prior to an application of Tenacity. This is especially important for pre-emergent weed control.
You can water the lawn after the the Tenacity Herbicide has dried. You can mow your established lawn 2 days after Tenacity Herbicide application.
When using Tenacity Herbicide or other post-emergent herbicides, you should not mow at least 2 days before or 2 days after applying the product. You should avoid spraying on newly germinated turgrass plants, and wait until newly germinated turf has been mowed 2 times or 4 weeks after emergence (whichever is longer) before applying, per the product label. Regarding watering, Tenacity is rainfast within a few hours of application, so I would avoid watering within about 3 hours of post-emergent applications. For pre-emergent applications, you will need to irrigate the area with 0.15 inches of water if there has not been this amount of rainfall within 10 days of application. There are no restrictions on fertilizing schedules. Keep in mind that desirable turf may discolor slightly to white or yellow, but listed tolerable turf should recover well. If you are using a fertilizer that can stress the lawn, then it may be a good idea to separate applications by 1-2 weeks. Please let us know if we may further assist you.
Tenacity Herbicide should be applied and completely dried prior to allowing anyone (including animals) to return to the treated surfaces.
Tenacity is labeled for use on St Augustine grown for sod only and would not be recommended on a home lawn. Could you tell us what you are trying to treat for and we can try to recommend a product that you can use?
Tenacity is labeled for postemergent control of nutsedge. However, the product label does state that weed control with postemergence applications require a second application after 2 to 3 weeks. You should also make sure that you apply the Tenacity to young, actively growing weeds with a non-ionic surfactant.
According to the Tenacity product label for smaller applications, you will need to mix 0.5 tsp of Tenacity and 1.5 tsp of surfactant to one gallon of water covering 1,000 sq ft.
Tenacity should be applied with a non-ionic surfactant to achieve the best results. Please refer to the product label instructions for details on mixing and application.
Per the Tenacity label, you will not exceed 5 fl. oz. of product per acre for fine fescue. This is just the max amount that should be used per year and per acre. The rate that should be used is you will need to mix 0.5 tsp of Tenacity and 1.5 tsp of surfactant to one gallon of water covering 1,000 sq ft. Also, Tenacity should NOT be applied at the time you are putting down new seeds or overseeding. This will likely inhibit their growth. You will want to wait until the lawn has been established before applying this product for pre-emergent control. This is generally after three mowings. There are no restrictions for Tenacity with regards to post-emergent control of weeds.
Tenacity will be most effective when temperatures are around 55 degrees. A non-ionic surfactant should be added in post-emergence applications.
Tenacity Herbicide does cause whitening of plants since its mode of action is to prohibit chlorophyll production in target plants. Many users have had whitening on the lawn after applications, but the grass usually does recover after 3-4 weeks. The product label specifies that Tenacity be used at lower rates for St. Augustinegrass, and only on established sod St. Augustine; St. Augustine lawns started from seed may have more sensitivity Tenacity. If the grass is still growing and needing to be mowed, then it will usually recover. You may want to wait several weeks to be sure future applications will not permanently damage your turf. Also, be careful so that your application is even and not overlapping, and that you are using a surfactant when making your application. You may also want to consider adding a turf marker such as Turf Mark Blue to prevent over-application.
Tenacity is not labeled to be used on bahiagrass. The most effective product to control Nimblewill pre-emergently has been removed from the market (MSMA). We have had a lot of folks report that Dimension does a pretty good job pre-emergently but since the product is not technically labeled for Nimblewill we cannot legally recommend it for this use. The usual recommendation since the ban of MSMA is to use a non-selective product such as Round Up on the weed, wait 14 days and re-seed or sod the area.
When using Tenacity Herbicide a broadcast application would be considered spraying over the entire lawn area. A spot treatment is used when you only have certain spots or areas that need to be treated versus the entire lawn. For most post-emergent applications with Tenacity, you will just spot treat to avoid whitening the desirable turf. Please follow the specific directions on the product label for your needs.
Tenacity Herbicide is not labeled as safe for use around Mondo or Monkey Grass. Surflan has been used for pre-emergent control of broadleaf weeds in Mondo Grass and for post-emergent control, Sedgehammer is commonly used. Please refer to the product lable for instructions and applications rates.
Surflan - Preemergence weed control when applied to established ornamental plants before weeds have emerged. This product performs better with incorporation after application with irrigation, rainfall or light tillage.
Sedgehammer - Apply in landscaped areas with established woody ornamentals. Do not apply over-the-top of flowers, ornamentals, shrubs or trees.
Post-emergent herbicides like Tenacity Herbicide work best when the plant is young and actively growing. Since that is what you are currently seeing, now would be a good time for the first application.