Herbicide label
Flexstar
Flexstar (EPA 100-1101) is a Group 14 fomesafen herbicide labeled for 1 crops. The label lists 47 controlled weeds, plus partial-control, suppression, and partner-control categories.
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“Flexstar is a selective herbicide which may be applied preplant, preemergence and/or postemergence for control or suppression of broadleaf weeds, grasses and sedges in soybeans.”
Flexstar label facts
- Product Flexstar
- EPA Reg. No. 100-1101
- Registrant Syngenta Crop Protection, LLC
- Active ingredient fomesafen
- MOA group 14
Crops on the Flexstar label
Flexstar is labeled for these 1 crops and uses, per the EPA label.
- soybean
Need the rate or timing for one of these? Filter every label by your crop, free.
Weeds on the Flexstar label
The Flexstar label names 69 weeds and rates each by how the product handles it: full control, partial control, suppression, or control with a tank-mix partner. A weed can fall at more than one level, because control varies by crop, rate, and timing.
Controls
full control47- amaranth, palmer
- amaranth, spiny
- anoda, spurred
- balloonvine
- carpetweed
- citron (wild watermelon)
- cocklebur, common
- copperleaf, hophornbeam
- copperleaf, virginia
- crotalaria, showy
- croton, tropic
- cucumber, volunteer
- eclipta
- groundcherry, cutleaf
- hemp
- jimsonweed
- ladysthumb
- mexicanweed
- morningglory, cypressvine
- morningglory, entireleaf
- morningglory, ivyleaf
- morningglory, palmleaf
- morningglory, pitted
- morningglory, purple moonflower
- morningglory, red (scarlet)
- morningglory, smallflower
- morningglory, tall
- mustard, wild
- nightshade, black
- pigweed, redroot
- pigweed, smooth
- poinsettia, wild
- purslane, common
- pusley, florida
- ragweed, common
- ragweed, giant
- sesbania, hemp
- sida, prickly
- smartweed, pennsylvania
- smellmelon
- starbur, bristly
- sunflower, annual
- velvetleaf
- mallow, venice
- waterhemp, common
- witchweed
- rocket, yellow
Suppression
suppression22- barnyardgrass, common
- bindweed, field
- bindweed, hedge
- signalgrass, broadleaf
- crabgrass
- foxtail, giant
- foxtail, green
- foxtail, yellow
- goosegrass
- horsenettle
- johnsongrass, seedling
- lambsquarters, common
- milkweed, climbing
- milkweed, honeyvine
- nutsedge, yellow
- panicum, fall
- panicum, texas
- redweed
- sicklepod
- spurge, prostrate
- spurge, spotted
- trumpetcreeper
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Flexstar rates and plant-back
The label answers both with a table, not a single number. Here is what drives each answer.
Application rate
Your rate depends on your crop.
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Plant-back and rotation
Your interval depends on your application rate, the rotational crop, and your state, region, and rainfall — some intervals differ in AL, AR, CT, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, ND, NE, NH, NJ, NY, OH, OK, PA, RI, SC, SD, TN, TX, VA, VT, WI, and WV.
Get the interval for your rotation: build a program and FieldMarshal cites the exact plant-back for your rotational crop to the label line.
Flexstar FAQ
What weeds does Flexstar control?
The Flexstar label names 69 weeds, including palmer amaranth, spiny amaranth, spurred anoda, balloonvine, carpetweed, and citron (wild watermelon). Control varies by crop, rate, and timing.
What crops is Flexstar labeled for?
Flexstar is labeled for 1 crops and uses, including soybeans.
What is the active ingredient in Flexstar? Is it a generic?
Flexstar's active ingredient is fomesafen (MOA Group 14). Other products list the same active ingredient; rates, formulations, and labeled crops differ — verify each on its own label.
What's the plant-back interval after Flexstar?
It depends on your rotational crop, application rate, and region, so the label gives a table, not one number. Build a program and FieldMarshal cites the exact interval for your rotation to the label line, so you can verify it.
Build a program →Can I tank-mix Flexstar?
It depends on your target weeds, crop stage, and which partners the label approves. Build a program and FieldMarshal checks the label for approved partners and cites the condition on each, so you can verify it.
Build a program →Plan in minutes, not evenings.
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Sources
Last updated 2026-07-10.