General Information


RONSTAR G Herbicide is a preemergent herbicide for control of many annual grasses and broadleaf weeds in turf and on a wide variety of woody ornamental shrubs, vines, and trees. RONSTAR G Herbicide controls weeds by killing the weed seedlings as they come in contact with the herbicide during germination. Apply RONSTAR G Herbicide with a properly calibrated granular applicator that will apply the granules uniformly (uniform application is essential for satisfactory weed control). Calibrate the applicator prior to use, according to the manufacturer's directions, and check frequently during the application to be certain that the equipment is working properly.

For best results, water-in the product as soon as practical after application.

Limitations, Restrictions, and Exceptions


For use in established perennial Bluegrass, Bentgrass, Bermudagrass, Buffalograss, Perennial Ryegrass, St. Augustine grass, Seashore Paspalum*, Tall Fescue, and Zoysia turf; such as, fairways, parks, golf courses, and lawns. Rake turf area free of leaves, mowing if necessary, so granules reach soil surface. Measure area to be treated and apply required amount, using a fertilizer spreader. Cross-treating with one-half required amount in each direction will give best results. Do not apply to wet turf. If rain is not expected shortly after application, irrigating the turf thoroughly will increase effectiveness.


Apply in late summer to early fall prior to Poa annua spp. seed germination. Any Poa annua spp. established when this product is applied will not be controlled. RONSTAR G Herbicide will only control the Poa annua spp. that is established from seed every year. Do not overseed fairways before 60 days after an application of RONSTAR G Herbicide. NOTE: Do not use where Poa trivialis is present in overseed mix.

NOTE: In many areas, annual bluegrass exists as at least two biotypes or subspecies of Poa annua. The true annual biotype is Poa annua sp annua which germinates every year from seed, while the biotype that behaves like a perennial is Poa annua sp reptans. This perennial biotype can survive through the summer and established plants will not be controlled by this product. Consult the extension service or University weed specialists in your area for more information.

For St. Augustine grass and Bentgrass turf, do not exceed the rate of 150 pounds per acre (3 pounds active ingredient) of RONSTAR G Herbicide.
RONSTAR G Herbicide may cause discoloration of Bentgrass, Bermudagrass and St. Augustine grass. This discoloration is temporary and normally outgrown within 2 to 3 weeks.

Avoid contact with flowers and shrubs except as discussed elsewhere on this label. Seeding into treated areas should be delayed until 4 months after treatment except as noted above. When making applications to Tropic Lalo, applications must be made 0 – 12 days after sprigging.

The maximum number of applications that may be made per year are two. The maximum single application rate is 200 lbs of product per acre per year (equivalent to 4 pounds of active ingredient per acre year).

The maximum application rate allowed per year is 300 pounds of product per acre per year (equivalent to 6 pounds of active ingredient per acre year), except in areas where there is heavy weed infestation. In areas of heavy weed infestation, the maximum application rate is 400 pounds of product per acre per year (equivalent to 8 pounds of active ingredient per acre year). For best results, water-in product as soon as practical after application.

- Do not apply to Bentgrass turf mowed at less than 3/8 inch.
- Do not apply RONSTAR G Herbicide to newly seeded areas.
- Do not apply to Dichondra or Centipedegrass.
- DO NOT APPLY RONSTAR G Herbicide to putting greens or tees because of the varying cultural practices used.
- Do not apply more than 4 pounds of active ingredient per acre per application.

Restricted Entry Interval

12 hours