General Information


RONSTAR FLO HERBICIDE is a selective, preemergent herbicide for control of many annual grasses and broadleaf weeds in turf and on a variety of woody ornamental shrubs and trees. RONSTAR FLO HERBICIDE controls weeds by killing the young weed seedlings as they come in contact with the herbicide during germination.

Apply RONSTAR FLO HERBICIDE with a properly calibrated sprayer that will apply the spray solution uniformly (uniform application is essential for satisfactory weed control). Calibrate the sprayer prior to use, according to the manufacturer’s directions and check daily to be certain that the equipment is working properly.

Do not allow domestic animals to graze treated areas. Avoid contamination of water intended for irrigation and domestic use.

Limitations, Restrictions, and Exceptions



Apply RONSTAR FLO HERBICIDE prior to weed seed germination as an over-the-top spray only.

AMOUNT TO USE: Apply broadcast, in a minimum of 1 gallon of water per 1000 sq. ft., to established ornamentals at 1.85 fl oz of product per 1000 sq. ft. Remove existing weed growth before application. Do not apply within 60 days of transplanting. Do not apply with adjuvants or drift control agents. Sprinkle irrigate within 2 hours after application, otherwise crop injury may result.

TANK-MIX COMBINATIONS: Ornamental Plantings and Noncropland areas

Tank-mix combinations of RONSTAR FLO HERBICIDE plus a non-selective herbicide such as FINALE are recommended to control existing undesirable vegetation. Applied as a directed spray, RONSTAR FLO HERBICIDE plus a non-selective herbicide such as FINALE will provide pre and postemergence control of susceptible species listed on the respective labels of the two herbicides.

PRECAUTION: Non-selective herbicides such as FINALE are not recommended as an over-the-top spray in ornamentals. Extreme care must be exercised to avoid contact of spray containing a non-selective herbicide with foliage, stems, green bark, or bare roots of desirable turfgrasses, trees, shrubs, or other desirable vegetation since severe damage or destruction may result. If spraying areas adjacent to desirable plants with a non-selective herbicide, use a shield made of cardboard, sheet metal, or plyboard while spraying to help prevent spray from contacting foliage of desirable plants.


- Not currently registered in California for use on Bristly Oxtongue, Cheeseweed, Fiddleneck, Fireweed, Shepherdspurse, and Sow Thistle.

- Common Groundsel, Evening Primrose, Galinsoga, Liverwort, Prostrate Spurge, and Swinecress: Use 2.8 fl oz of product per 1000 sq. ft.

- Not currently registered for use on Fir, Hemlock, and Blue Spruce in California.

Restricted Entry Interval

12 hours