Ronstar Flo Herbicide

This product is a restricted use pesticide and must have a certified applicator license to be able to purchase.

Ronstar Flo Herbicide, manufactured by Envu, is a reliable systemic, pre-emergent herbicide concentrate that aids professionals, landscapers, and groundskeepers with dependable, residual weed control all season long in turf and ornamentals.

This liquid pre-emergent contains oxadiazon 34.1%, which forms a protective barrier on the soil surface for at least 60 days. With once-per-season applications and broad-spectrum control, you can reduce follow-up herbicide treatments and spot sprays. That’s more time spent enjoying your property or managing other jobs - not playing catch-up on weed outbreaks.

Ronstar Flo Herbicide offers one of the most reliable turf and ornamental-safe pre-emergent solutions on the market today. With its flexible formulation, outstanding residual performance, and broad-spectrum weed control, it's ideal for professionals who demand precision and long-term results.

Tools Needed

A handheld pump sprayer, backpack sprayer, or spray rig can be used.

How to Use

• Step 1: Determine how much Ronstar Flo Herbicide to use by measuring the square footage of the treatment area. Find the square footage by measuring the treatment area's length and width in feet, then multiply them together (length X width = square footage). For acreage, take the square footage and divide them by one acre (square footage / 43,560 sq. ft. = acres). For turf, apply 1.85 to 2.8 fl. oz. of Ronstar Flo Herbicide in 0.75 to 3.5 gallons of water per 1,000 sq. ft. To treat ornamentals, mix 1.85 fl. oz. of product in 1 gallon of water per 1,000 sq. ft. 
• Step 2: Fill the sprayer tank with half the amount of water, add the proper amount of product, then pour in the remaining half of water. Close the spray tank lid and shake until well-mixed.
• Step 3: As a spot or broadcast, treat the soil evenly on a fan spray pattern. Do not spray to the point of runoff. After application (the same day), lightly irrigate the treated area. 

Where to Use

Ronstar Flo Herbicide can be used on dormant established turf. It may also be used for ornamentals and conifer nurseries.

Residential turf and ornamentals cannot be treated. Do not apply in greenhouses.

When to Use

Apply before weeds become present in late winter or early spring. 

An application to turf can only be done when it's fully established and dormant.

Application can be made to actively growing or dormant ornamental plants.

Safety Information

Ronstar Flo Herbicide is safe for people and pets when applied according to the product label instructions. Always wear the proper personal protective equipment (PPE) when mixing and applying this product.

Do not allow people or pets to enter treated areas until sprays have dried.

Special Considerations

Do not apply within 60 days of transplanting.