Active Ingredients % By Weight

Prodiamine............................0.40% Isoxaben................................0.25% OTHER INGREDIENTS:......................99.35% TOTAL:.....................………100.0%

Product Code


Gemini® Granular

Gemini® Granular

  • Advantages
  • Description
  • Use Sites & Rate Table

Gemini Granular® with patent pending R-50 Optimizer™ is a powerful, flexible weed management tool that controls 120+ weeds with a low risk of Phytotoxicity.  R-50 Optimizer™ gives Gemini® Granular the power to stop weeds with less active ingredient, allowing the weed manager to make more applications per year, or reduce the active ingredient applied per acre of nursery.

Gemini® Granular rate range goes from 100-200 pounds per acre per application with a maximum application rate per year of 375 lbs.  At higher rates, weed control will last longer.  Research has shown weed control at high rates for up to 4 months, and low rates 60-90 days.    

Whether the applicator is looking for a longer-duration pre-emergent herbicide that will be tolerated by a very broad range of crops, or a herbicide to slip into the window where the existing program doesn't quite hold up, Gemini® Granular with R-50 Optimizer™ is the right choice.  

Click for Product Brochure

Click for Tech Share on weed control

Click for Tech Share on R-50 Optimizer™ Technology

Click for Low Phytotoxicity Trial sheet done at Auburn University

Click for Low Phytotoxicity Trial sheet done at Mid-Florida Research & Education Center


Gemini® Granular with R-50 Optimizer™ is combination of Isoxaben, the active ingredient in Gallery®* pre-emergent herbicide, and Prodiamiine, the active ingredient in Barricade®* pre-emergent herbicide. R-50 Optimizer™ gives Gemini® Granular the power to control weeds with less active ingredient.  

Formulation and Mode of Action

Gemini® Granular is a herbicide containing the active ingredient, prodiamine, a member of the dinitroaniline family of herbicides (Group 3) which inhibits mitotic processes in plants, and isoxaben, which has a cellulose biosynthesis inhibitor (CBI) mode of action (Group 21). The actives control susceptible weeds by preventing growth and development of newly germinated seeds. Each bag contains 0.325 pounds active ingredient (0.2 pounds prodiamine per bag plus 0.125 pounds isoxaben per bag). Gemini® Granular is used for pre-emergent control of listed grasses and broadleaf weeds. Weed control is most effective when Gemini® Granular is activated by at least 0.5 inches of rainfall or irrigation.

*Barricade® is a trademark of a Syngenta Finance Corporation. Gallery® is a trademark of Dow AgroSciences LLC.
Use Sites & Rate Table

Use Sites*


Application Instructions

Newly-Transplanted Container or
Field Nursery Stock




• Do not apply until soil has settled around transplants and roots have formed.

• Do not apply to wet foliage as damage may occur.

• Apply after cuttings form roots and are established.

• To avoid inhibition of the tissue union, apply before budding/grafting or after    buds/grafts have taken.

• Do not apply to pots less than six inches wide

Established Container, Field Nursery Stock, or Landscape Plants

• Apply at any time as an over-the-top, or soil directed application.


Landscape (or Ornamental) Plantings

• Apply as an over-the-top, or as a soil directed application.

• Delay applications to newly transplanted ornamentals until soil has settled around  transplants.

Bare Ground Application for Container Placement



• Apply to soil (including mulch, gravel, wood chips, or other permeable base) upon  which containerized ornamentals are placed.

• After Gemini® Granular is applied, use post-emergence herbicides to control break  though weeds. Or if necessary, perform shallow cultivation or hand weeding to avoid  disturbing the herbicide barrier.

In Shadehouses and Uncovered Polyhouses


• After Gemini® Granular is applied, houses must remain uncovered for at least 21  days.

• In addition, plants must receive 2 irrigations totaling at least 0.5 inches of water  before covering.

Ornamental Bulbs (Not for use on ornamental bulbs grown for commercial production in California).

• Gemini® Granular can be applied to bulbs. Apply before bulbs emerge. Do not apply  after emergence.


Rate Table*


  Low Rate Medium Rate High Rate

Do Not Exceed The Maximum Annual Rate Of:

Pounds per Acre 100 150 200 375
Bags per Acre 2 3 4 7.5
Pounds per 1000 sq. ft. 2.3 3.4 4.6 8.6
Grams per sq. ft. 1.0 1.6 2.1


* Refer to the product label on the bag before using Gemini® Granular.  

Click for Specimen Label

Gemini® Granular is a pre-emergent herbicide with R-50 Optimizer™, a patent-pending technology to maximize performance.  The product features Prodiamine and Isoxaben; a combination proven to control more than 120 grassy and broadleaf weeds.

Product registered in the following states: AK, AL, AR, AZ*, CO, CT, DC, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, OH, OK, OR, PA, RI, SC, TN, TX, UT, VA, VT, WA, WI, WV, WY
*Landscape Only