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The Daily Insight

When should I spray trimec

Author

Christopher Lucas

Published Mar 23, 2026

Trimec can be applied any time weeds are visible in your yard and temperatures are 65–85℉ (18–29℃). Apply Trimec at least 24 hours before rain or lawn watering. This allows time for the herbicide to dry and fully infiltrate the plant system.

What temperature should I spray trimec?

Answer: When using Trimec 992 Broadleaf Herbicide the tempuratures would need to be above freezing, and the weeds would need to be actively growing in order for the product to work effectively. Most post-emergent herbicides such as Trimec will be most effective when temperatures are around 65-80 degrees.

Should I mow before applying trimec?

Answer: The Trimec Southern Broadleaf Herbicide does not specifically state if if mowing before or after is beneficial to the effectiveness of the application, but we generally recommend that you do not mow within 2 days of herbicide applications.

How soon can you apply trimec?

Wait 3-4 weeks after application before re-seeding. For new lawns, apply only when grass has reached a height of at least 2 inches and has been mowed at least 2-3 times.

How long does it take for trimec to kill weeds?

How long does Trimec take to kills weeds? According to Gordon’s website, the product should begin to work within 4-6 hours of application but will take 2-4 weeks depending on plant age and health. This holds true for most weeds. Trimec will kill both dandelion and clover in about two weeks.

How long should I wait to mow after spraying trimec?

Answer: It is recommended to mow 3 days before Gordons Trimec Classic Broadleaf Herbicide application and then you can mow 3 days after application.

How long should trimec be applied before rain?

Apply Trimec at least 24 hours before rain or lawn watering. This allows time for the herbicide to dry and fully infiltrate the plant system. Trimec is a powerful herbicide that should be used no more than 2 times per year, with at least 30 days between applications.

Can I overseed after using trimec?

Answer: Areas treated with Trimec 992 may be reseeded after 3 weeks. After you have put down new seed, you should wait until after the second mowing to new seedlings to use Trimec 992.

Can you spray trimec in the summer?

Apply Trimec in the spring or early summer if you seed with cool-season grasses. These seeds prefer cool, early fall temperatures between 60 and 75 degrees Fahrenheit for germination. Avoid any seeding in late fall, however, because germination rates are considerably reduced.

How do you spray trimec?

Mix 1 fluid ounce (2 Tablespoons) of Trimec® Ready Spray Lawn Weed Killer in 1⁄2 gallon of water in a pressure sprayer. Spray to wet individual weeds.

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When Should I spray my lawn with par 3?

TIMING: Par III can be applied to established turf at any time during the growing season when weeds are young and actively growing. Apply in good growing conditions before crop canopy shields the weeds. Do not apply to newly established turf until after second to third mowings.

How soon can you water after applying trimec?

We recommend that you apply the Gordons Trimec Classic Broadleaf Herbicide on a day when you are not expecting any rainfall. You should not irrigate 24 hours after application of the product also per the product label instructions.

Should I spray for weeds before or after mowing?

To get good contact with the weed, don’t mow the grass before applying weed killers. Mowing eliminates the weed’s surface area and ultimately decreases the success of the weed killer. Plan to leave your grass uncut for two days after application and five days before.

How much is trimec a gallon of water?

Use 0.75 oz. of Trimec Southern Broadleaf Herbicide per gallon of water per 1,000 sq. ft. of bermudagrass, bentgrass, bluegrass, fescues, and zoysiagrass.

Will trimec kill crabgrass?

Kills broadleaf weeds and crabgrass in one convienient application. Trimec is safe to use on your lawn for getting rid of crabgrass and over 200 troublesome weeds.

Does trimec kill clover?

Gordon’s ® Trimec ® Lawn Weed Killer kills more than 250 kinds of weeds including dandelion and white clover without harming your lawn when used as directed.

Can I spray trimec in the fall?

Answer: Trimec 992 Broadleaf Herbicide can be sprayed when weeds are actively growing through October before the soil temperatures reach 55 degrees Fahrenheit. Please check out our Cool Season Lawn Schedule for a wonderful guide that shows when to treat your lawn.

Will trimec hurt trees?

Some of these go into the ground with water and the trees and shrubs will take them in through their roots. These sprays can be very injurious to trees and shrubs. … Neither should Trimec or Weed B Gon Max be used within the rooting zone of trees.

What is the shelf life of trimec?

Gordons Trimec Classic Broadleaf Herbicide has a shelf life of 2-3 years if stored at room temperature.

Is trimec volatile?

Controls dandelions, chickweed, knotweed, clover, plantain, henbit, spurge, kudzu, and many other broadleaf weeds in turf and lawns. This is the Trimec® complex for cool weather control of hardened-off mature weeds. The low volatile ester formulation penetrates even the toughest weeds.

Does trimec need a surfactant?

Answer: A surfactant is not required when using Gordons Trimec Classic Broadleaf Herbicide. However, you can use one in order to increase the effectiveness of the product and help it adhere to plants more effectively.

What temperature should you apply herbicide?

The ideal temperature for applying most post-emergent herbicides is between 65° F and 85° F, but this is not always possible. Burndown herbicides may be applied at temperatures from 40° F to 60° F, but this may cause slow weed control to take place, as noted above.

How fast does trimec 992 work?

Developed for the professional lawn care operator, Trimec 992 is formulated to reduce costs and provide effective control – some weeds begin to show injury within hours. Trimec 992 is rainfast in as little as eight hours, and treated areas can be reseeded in three weeks.

Can you mix MSMA and trimec?

Answer: Yes, Trimec 992 Broadleaf Herbicide can be tank mixed with MSMA 6 Plus by following the Tank Mixing instructions on the product labels.

Will trimec hurt dogs?

Trimec 992 Broadleaf Herbicide is pet safe when used as directed. Pets and people need to be kept away from the treated area during application and until everything is fully dry. Once everything is dry, it is fine to resume normal activity. If pets chew on the grass, it won’t harm them once dry.

Is Par 3 harmful to dogs?

The activity of the low dosage required when using PAR III in a spray mixture is effective on weeds, without being harmful to people and animals including pets, birds and insects. The amount applied is small and provides a large safety factor.

Is Par 3 banned in Canada?

If you see a bottle of Par 3 in the back of a pickup truck, is this illegal? Spotting Par 3 in a residential area out in the open raises major red flags, both McIntosh and Dawson agree. “First of all, Par 3 must be locked in a compartment if it is unsupervised, so that it’s not accessible to the public,” Dawson says.

What kills mature crabgrass?

The best weapon in your quest to kill crabgrass is pre-emergence herbicide (also called crabgrass preventer). Apply it in the spring before the crabgrass seeds sprout. The granular herbicide works by creating a chemical barrier at the surface of the soil. As the seeds germinate, they take in the herbicide and die.

What is the best time of day to spray weeds?

Systemic herbicides work best when applied late morning, midday and in the afternoon in cool or cold climates. Plant growth slows down at dusk and speeds up again as the sun rises the following day. Heavy early morning dew can cause herbicides to run off, so it’s best apply them after dew has evaporated.

Should you trim weeds before spraying?

DO NOT mow before you spray. Roundup works by contact with the leaves on the plant. You’d get a kill if you mow but it would work better if you spray on the weeds before you mow.

What is the mix ratio for trimec?

Gordons Trimec Classic Broadleaf Herbicide is mixed anywhere from 0.75 – 1.5 oz. per 0.5 to 6 gallons of water per 1,000 sq ft. depending on what and where you are treating.