Trimec® Weed Killer
Trimec kills the dandelion and leaves the grass standing. Three active ingredients handle more than 230 listed broadleaf weeds in an established lawn, at a mixing rate that depends on which turf you have.
Trimec Sizes and Coverage
- 1 Quartup to 8,000 sq. ft.
Spot work and smaller lawns.
up to 16,000 sq. ft. at the reduced rate · Item #791600 · UPC 070251791606
- 1 Gallonup to 32,000 sq. ft.
Repeat treatment across a large yard.
up to 64,000 sq. ft. at the reduced rate · Item #792000 · UPC 070251792009
- 2.5 Gallonsup to 80,000 sq. ft.
Acreage, where gallon jugs pile up.
up to 160,000 sq. ft. at the reduced rate · Item #792900 · UPC 070251792900
Buying by coverage instead of price
A 5,000 sq. ft. fescue lawn takes 20 fl. oz. of concentrate for one broadcast pass, so a full season of two passes runs 40 fl. oz. A quart holds 32. Concentrate keeps for 3 to 5 years in its original container, which is why the gallon usually costs less per treated square foot than buying the quart twice.
| Type | Selective post-emergent concentrate |
|---|---|
| 2,4-D, dimethylamine salt | 7.59% |
| Mecoprop-p, dimethylamine salt | 1.83% |
| Dicamba, dimethylamine salt | 0.84% |
| Other ingredients | 89.74% |
| Weeds controlled | 230+ listed broadleaf weeds |
| EPA Registration No. | 2217-539-33955 |
| Shelf life | 3 to 5 years, stored as directed |
Will Trimec Kill My Grass?
Standard rate
4 fl. oz.per 1,000 sq. ft.
- Bahiagrass
- Bermudagrass
- Fescues
- Kentucky bluegrass
- Perennial ryegrass
- Zoysiagrass
Half the rate
2 fl. oz.per 1,000 sq. ft.
- Centipedegrass, compatible varieties
- St. Augustinegrass, compatible varieties
Tolerance across these two runs from sensitive to tolerant, which is why the rate is halved. Putting the northern number on a southern lawn applies twice what that turf was meant to take.
Never
- Carpetgrass
- Dichondra
- Floratam St. Augustinegrass
Identify the lawn first
Guessing between bermudagrass and St. Augustinegrass means guessing between two rates that differ by half. Both spread by runners and both look coarse from standing height, so check a single shoot at ground level before anything goes in the sprayer. A county extension office will identify a photo for free.
What Trimec Does Not Kill
Crabgrass, foxtail and other grassy weeds
Crabgrass is a grass, and this formula was built to leave grasses alone. Spraying it on a crabgrass patch wastes the application. Gordon’s Trimec Crabgrass Plus is the formula carrying emerged crabgrass, foxtail and signalgrass on its label alongside 200+ broadleaf weeds.
Nutsedge and kyllinga
Sedges are a separate plant family and they survive a straight broadleaf herbicide. A lawn where the tall, glossy, triangular-stemmed shoots keep reappearing three days after mowing needs Trimec Platinum All-In-One, which carries five active ingredients and lists sedges and kyllingas.
Weeds that have not come up yet
Nothing here stops seed from germinating. Trimec works on foliage that already exists, so a lawn sprayed clean in April can carry a fresh flush of summer weeds by June. Preventing that generation is a pre-emergent job, done before the seed wakes up.
Overnight results
Trimec Lawn Weed Killer is judged by whether the weed dies, not by how fast the leaf changes color. A dandelion still standing on day three has not survived. Where speed genuinely matters, Trimec Speed is the separate formula listing visible results in 8 hours.
Clover you planted on purpose
White clover appears on the weed list, and the herbicide cannot tell a clover you seeded from one that arrived on its own. The same applies to flower beds, vegetable rows and ornamental shrubs, since those are broadleaf plants too.
Choosing the right Trimec
| Formula | Built for | Rainfast | Coverage |
|---|---|---|---|
| Trimec Lawn Weed KillerThis page | 230+ listed broadleaf weeds in established turf | 24 hours | 32,000 to 64,000 sq. ft. per gallon |
| Trimec Speed | 250+ broadleaf weeds, visible results in 8 hours | 2 hours | up to 10,600 sq. ft. per quart |
| Trimec Crabgrass Plus | Emerged crabgrass, foxtail and signalgrass, plus 200+ broadleaf weeds | See container | up to 5,000 sq. ft. per quart |
| Trimec Platinum All-In-One | Broadleaf weeds, crabgrass, listed sedges and kyllingas | 2 hours | up to 5,000 sq. ft. per quart |
Rates are not interchangeable between these formulas. Trimec Crabgrass Plus is also not approved for sale or use in New York State.
What Weeds Trimec Kills
Crabgrass and nutsedge are not on this list. Here is what handles those.
The regulars
- Common dandelion
- White clover
- Red clover
- Chickweed
- Henbit
- Ground ivy (creeping Charlie)
- Broadleaf plantain
- Buckhorn plantain
- Wild violet
- Oxalis
- Dollarweed
- Spotted spurge
Harder targets
- Canada thistle
- Bull thistle
- Prostrate spurge
- Ragweed
- Wild onion
- Wild garlic
- Common purslane
- Lambsquarters
- Speedwells
- Poison ivy
- Poison oak
Broad leaves are not the test
Asters, bedstraws, bindweeds, buttercups, docks, fleabanes, hawkweeds, mallows, morningglories, mustards, pigweeds, vetches and yarrows all appear on the label in multiple species.
Control still depends on the weed being named on the container rather than on the plant simply having wide leaves. Young weeds in active growth go down most reliably. A mature, hardened plant sometimes survives the first pass and needs a spot treatment later.
How to Mix and Spray It
Measure before you mix
Multiply length by width for a rectangular lawn. Break an irregular one into sections, work each out separately, then add them up. Leave out the driveway, the patio and the planting beds.
A 15,000 sq. ft. property often holds only 8,000 sq. ft. of actual turf once the house and hardscape come out, and paying for the difference in concentrate is the common version of this mistake.
Spot treatment
| Lawn | Per gallon | Treats |
|---|---|---|
| Standard-rate lawns | 1 fl. oz. | 250 sq. ft. |
| Centipede and St. Augustine | 0.5 fl. oz. | 250 sq. ft. |
Scattered weeds in an otherwise clean lawn are cheaper to spot treat than to broadcast over.
Pump sprayer
Add the water and the measured concentrate to the tank, close it, shake it well, then pressurize. Set the nozzle to a coarse spray rather than a fine mist, since fine droplets travel. For spot work, wet the leaf surfaces of the weed and stop there.
Hose-end sprayer
On a dial-style unit, put enough concentrate in the jar for the whole treatment area without diluting it first, then set the dial to 1 oz. The sprayer meters it into the hose water as you walk. Other hose-end designs want water added to the jar up to their own markings, so read the sprayer as well as the herbicide.
12-volt and tow-behind
Boom equipment gives more even coverage across a large yard than refilling a hand tank eleven times. Calibrate speed and pressure to put out 0.5 to 1 gallon of spray solution per 1,000 sq. ft., then hold that speed. Directions for 15-gallon and 25-gallon units are printed on the container.
Two different one-ounce numbers
The dial setting on a hose-end sprayer is 1 oz., and it tells the sprayer how much concentrate to pull into every gallon of hose water it passes. The spot-treatment figure is also 1 fl. oz., but that one is the whole amount of concentrate going into a one-gallon hand tank to cover 250 sq. ft. Same number, unrelated jobs. Reading one as the other is how a lawn ends up burned.
Watch it done end to end
When to Spray, and How Long Before Rain
60°F to 90°F, on weeds that are growing
A weed that has stopped growing takes up very little of anything. Aim for moderate weather and moist soil, and skip the application during a heat wave. Spring and fall usually supply those conditions, though the thermometer decides rather than the month. Warm-season lawns also stay untreated through spring transition.
Water the day before, not the day after
Dry soil is worth correcting before you spray. Irrigate roughly 24 hours ahead so the weeds are actively growing when the spray lands. Watering straight after the application does the opposite and rinses the herbicide off the leaves it needed to sit on.
Rainfast in 24 hours
Keep the lawn dry for a full day after treating, and that covers the sprinkler system as much as the forecast. Rain inside the window is the single most common reason a correctly mixed application appears to do nothing. Other Trimec formulas have their own intervals, so do not carry this number across to them.
Mow first, then wait 1 to 3 days
Cutting the lawn immediately before spraying removes the leaf surface the herbicide has to land on. Mowing straight afterward strips treated foliage before the plant has moved anything downward. Set the mowing day first and the spray day follows it.
Wind matters as much as temperature. Spray that drifts off the lawn lands on something that was never meant to receive it.
How Often You Can Spray, and Seeding After
Two broadcast treatments a year
Residential turf takes two broadcast passes in a season, and a 30-day gap has to separate them. Each pass is capped at 4 fl. oz. per 1,000 sq. ft., with 8 fl. oz. per 1,000 sq. ft. standing as the total for the whole year. Spot work carries the same ceiling and the same wait.
A survivor is a timing problem, not a dose problem
Established weeds sometimes come through the first pass. Mixing the second application stronger is not the fix and puts the lawn at risk; hard-to-kill weeds can be spot treated again once 30 days have passed. Most escapes trace back to a weed that was too mature, too dry or mowed too recently.
Seeding after treatment
Bare spots can be seeded 3 to 4 weeks after an application. Plan that gap before a renovation, because spraying the week before you overseed puts weed control and new turf in direct conflict.
Seeding before treatment
New grass should reach at least 2 inches before it meets a selective herbicide, and Gordon’s puts the safer threshold at a lawn that has already taken two or three cuts. Young turf that has not rooted properly carries very little margin.
Handling It Around People, Pets and Plants
What to wear
Trimec Lawn Weed Killer carries the signal word CAUTION. Handling it calls for a long-sleeved shirt, long pants, socks, shoes and gloves. Keep it off skin, eyes and clothing, and wash thoroughly afterward.
People and pets
Keep both out of the area while you spray. Everyone can come back once the spray has dried. Drying is not a fixed number of minutes, because sunlight, temperature, humidity and how much solution went down all change it.
The plants you want to keep
Selective means selective among listed turfgrasses, not harmless to everything green. Keep spray off desirable plants, off exposed roots, and out from under the drip line of trees and shrubs. A fine mist raises the odds of hitting something you meant to spare, so use a coarse pattern and shut the sprayer off before crossing a bed.
Water and drains
This product is toxic to fish and aquatic invertebrates. Keep it out of storm drains, drainage ditches, gutters and surface water, and stay 25 feet back from rivers, ponds, lakes, streams, reservoirs, marshes, estuaries, bays and oceans. Rinse equipment over the lawn you just treated rather than over pavement.
Storage
Store the concentrate in its original container, in a locked place children and pets cannot reach, and protect it from freezing. An unheated garage in January is the wrong spot for a part-used jug.
Empty containers
The container is nonrefillable and should not be reused for anything. Unused product never goes into an indoor or outdoor drain. Follow the disposal instructions printed on the container.
Customer Reviews
MUCH better than ANY other brand I've tried to kill weeds in my grass area. Just follow instructions.
Mountain Cowboy
i sprayed it on my lawn & you won't get dandelions in the spring, great product
Dale Schertz
Awesome for removing weeds without killing your grass. This is a post emergent. Best if used on full lawn and spot treatment of crabgrass, thistle, dandelion and other hard to treat weeds. May need more than on...
jason Moulder
This is approved for use in Colorado with the most stubborn of weeds ... esp. the type that didn't die using roundup or weed b gone. After 3-4 days I noticed them turning colors and dying off. This is now my to...
Doc Savage
Works as advertised. Used with surfactant for maximum effect.
BILL
I’ve been using this product on my lawn for years, mostly for dandelions. Only issue I have ever had was with me not mixing correct amount so I only made the weeds sick, but outside of that I highly recommend.
Redrocker118
Gordon’s, and Where Trimec Came From
PBI-Gordon began in 1947 as Private Brands, Incorporated. The company bought Gordon Chemical Company in 1956, then picked up the patent for the Trimec broadleaf herbicide during the 1960s, while the turf industry was expanding fast enough to need it. Trimec is one of the products that turned PBI-Gordon into a major turf-care manufacturer.
The company became fully employee-owned in 2002. Trimec Lawn Weed Killer is still manufactured and distributed by PBI/Gordon Corporation out of Shawnee, Kansas, and Trimec remains a registered trademark of PBI-Gordon Corporation.
Half a century of regulatory and product-development changes have moved the formula more than once. That is the reason a Trimec mixing instruction remembered from a neighbor, a forum post or an older jug is worth nothing against the container in your hand. Application rate, turf restrictions and state registration all come from the product you actually bought.
What has not changed is the idea behind it. Selective broadleaf control for established lawns, sold as a concentrate so a pump sprayer and a tow-behind boom can both run the same product at a rate matched to the property.
Frequently Asked Questions
Trimec Lawn Weed Killer is a concentrated selective herbicide made for controlling broadleaf weeds in established lawns. The formula combines three herbicidal active ingredients and controls more than 230 weeds listed on the product label. Because it is selective, Trimec can be applied to many common turfgrasses without killing the lawn when mixed and applied according to label directions. It is a post-emergent herbicide, meaning the target weeds should already be growing when the product is applied.
Trimec Lawn Weed Killer is manufactured and distributed by PBI-Gordon Corporation, a U.S. company based in the Kansas City area. PBI-Gordon traces its history to 1947 and has specialized in turf, lawn and agricultural products for decades. The company acquired the patent for Trimec broadleaf herbicide during the 1960s. Trimec subsequently became one of PBI-Gordon’s best-known turf-care product families and has been used for broadleaf weed control for more than 50 years.
Trimec Lawn Weed Killer controls more than 230 broadleaf weeds listed on its label. Common targets include dandelion, white clover, chickweed, ground ivy, plantain, thistle, wild violet, oxalis, henbit and spurge. Many less common broadleaf species are covered as well, but weed identification still matters. Trimec should not be assumed to control a plant simply because it is growing as a weed in the lawn.
Standard Trimec Lawn Weed Killer is primarily designed for broadleaf weeds and is not the appropriate Trimec product for controlling crabgrass. Gordon’s Trimec Crabgrass Plus Lawn Weed Killer is specifically formulated for emerged crabgrass and certain other grassy weeds in addition to broadleaf weeds. Trimec Platinum All-In-One is another option for lawns containing a mixture of broadleaf weeds, crabgrass and certain sedges. Check the exact product name before mixing because application rates differ between Trimec formulas.
Trimec Lawn Weed Killer is selective and is designed to control broadleaf weeds without harming compatible lawn grasses when used as directed. Established bahiagrass, bermudagrass, fescues, Kentucky bluegrass, perennial ryegrass and zoysiagrass all take the standard rate. Compatible centipedegrass and St. Augustinegrass can also be treated, but they require a lower application rate. Trimec should not be used on carpetgrass, dichondra or desirable clovers. Improved St. Augustinegrass varieties such as Floratam are also restricted.
For bahiagrass, bermudagrass, fescues, Kentucky bluegrass, perennial ryegrass and zoysiagrass, mix 4 fl. oz. of Trimec in enough water to treat 1,000 sq. ft. One gallon of water is commonly used for that area. For compatible centipedegrass and St. Augustinegrass, use the lower rate of 2 fl. oz. per 1,000 sq. ft. The amount of concentrate should be based on square footage and turf species rather than simply on the capacity of the sprayer.
A 1-gallon container holds 128 fl. oz. of concentrate. At the standard rate of 4 fl. oz. per 1,000 sq. ft., one gallon treats approximately 32,000 sq. ft. At the reduced 2 fl. oz. rate used on compatible centipedegrass and St. Augustinegrass, the same container can treat approximately 64,000 sq. ft. Actual coverage depends on the grass species and labeled application rate.
Trimec Lawn Weed Killer can be applied with several common lawn sprayers. Pump-up sprayers work well for smaller lawns and spot treatments. Hose-end sprayers can cover larger residential areas with less refilling, provided the sprayer is calibrated correctly. Tow-behind and 12-volt boom sprayers are practical for larger properties. Regardless of equipment, the goal is to distribute the labeled amount of herbicide evenly over a measured area. A coarse spray pattern also helps reduce off-target drift.
Apply Trimec when the weeds are actively growing and the lawn is not under severe environmental stress. Suitable conditions run around 60°F to 90°F with adequate soil moisture. Avoid spraying during very hot weather, strong wind or when rain is expected shortly after application. Spring and fall often provide suitable conditions, but temperature and weed growth matter more than the season alone. Warm-season turf should not be treated during vulnerable spring transition periods.
Trimec Lawn Weed Killer is considered rainfast 24 hours after application. Avoid rainfall or irrigation during that period so the herbicide has adequate time on the treated foliage. If the lawn is dry before treatment, watering approximately a day before spraying is preferable to watering immediately afterward. Other Trimec products can have different rainfast periods, so instructions for Trimec Speed or Trimec Crabgrass Plus should not be applied to standard Trimec Lawn Weed Killer.
For best results, mow before treatment and apply Trimec approximately 1 to 3 days later. This gives weeds time to retain or produce enough exposed leaf surface for effective herbicide contact. Mowing immediately before spraying can remove foliage that would otherwise absorb the treatment. Avoid rushing to mow immediately after application as well. Allow the treatment to remain on the weeds and follow the mowing guidance on the current product label.
Residential broadcast treatment is limited to two applications per year with at least 30 days between them. A second treatment may be useful when established or difficult weeds survive the first application, but increasing the concentration above the labeled rate is not a substitute for correct reapplication timing. Always check the container before treating because application limits and state-specific restrictions can change.
Wait approximately 3 to 4 weeks after applying Trimec before reseeding treated areas. Newly established grass should also be mature enough before Trimec is applied, which means new turf at least 2 inches in height that has been mowed two or three times. This timing allows young turf to become better established before exposure to a selective post-emergent herbicide.
People and pets should remain out of the treatment area during application and can re-enter once the spray has completely dried. Drying time varies with sunlight, temperature, humidity and the amount of spray applied, so there is no single drying time that applies to every lawn. The concentrate should remain in its original container and be stored where children and pets cannot access it. Applicators should follow the personal protective equipment requirements printed on the current label.
Trimec Lawn Weed Killer generally has a shelf life of at least 3 to 5 years when stored according to label directions. Keep the concentrate in its original container and protect it from freezing. Storage areas should be secure and inaccessible to children or pets. Older product should still be checked for label condition and proper storage history before use. If application directions on an older container differ from current online information, follow the legally applicable label attached to the product rather than relying on instructions for a newer formulation.
Match the Weed and the Grass
Name the weed. Name the turf. Measure the area that will actually be sprayed. Wait for a day the weeds are growing and the sky is clear. Those four answers give you the rate, and the container carries the one that applies to your lawn.
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