When harvest wraps up, you might be tempted to park the sprayer. But skipping fall weed control could cost you next spring.
Benefits of a fall burndown herbicide
Your next crop can benefit from fall herbicides because a burndown treatment can:
- Limit overwintering pests: Fall burndown helps limit pests and pathogens that would ordinarily make their homes in winter weeds.
- Reduce spring weed biomass: Avoid plentiful spring weeds that can make planting a tougher job than it needs to be.
- Curb weed competition: Give your crops a chance to develop a strong stand and produce higher yields in the upcoming growing season by pushing back on weeds that steal valuable nutrients and water.
- Find potential economic advantages: Avoid the extra expense of labor and fuel managing excess weeds at planting time, plus ensure you use fall burndown herbicide only where you need it when weather and temperature are optimal.
Timing considerations for fall weed control
It’s best to make a fall herbicide application when fall weeds are actively growing. This occurs when daytime temperatures are 50 F or greater, typically from late October to mid-November.¹
Identifying problem weeds for fall burndown herbicides
In late summer or fall, scout for winter annuals such as marestail that have entered the rosette stage. This means the weeds appear in small clumps at the soil surface.²
Next, use weed-identification apps, websites, insights from trusted advisers and your own experience to determine which species you’re dealing with. This will help you determine the right combination of herbicides and genetics plus biological, cultural and mechanical control methods.
Ideal conditions for burndown herbicide application
Scout corn and soybean fields to determine your burndown needs. Fall burndown herbicides usually perform best when temperatures are between 60 F and 75 F at application.³ These conditions should remain for several hours post-application for maximum effectiveness.
You can improve the efficacy of your herbicide with an adjuvant.⁴ These oil-based solutions are especially effective in drier environments with low relative humidity. They slow the rate at which droplets dry, giving herbicide more time to work its way into weed leaves.
For fall burndown applications, several products from BASF can be helpful, including:
- Distinct® herbicide: Tackle major broadleaf weeds including waterhemp and Canada thistle with this burndown for corn, soybean and cotton fields.
- Sharpen® herbicide: Fight kochia, marestail and waterhemp in corn and soybean fields.
- Verdict® herbicide: Combat broadleaf weeds with this burndown for soybeans, corn and grain sorghum fields.
- Zidua® brand herbicides: Target Palmer amaranth, waterhemp and more with long-lasting effects.
Herbicide and tank mix strategies
Following are some general rules of thumb. For more specifics, work with a trusted adviser such as your regional BASF representative to determine the best burndown herbicide and fall burndown strategy.
Glyphosate
More active in warmer temperatures compared to 2,4-D, which can perform better in colder conditions.
2,4-D
A bit more active than glyphosate when conditions are below 40 degrees F. Should be tank-mixed with a residual in most cases.
Tank mixing with residuals
This can be a good post-harvest option in cooler conditions when foliar herbicide applications are generally less effective.⁵
One common fall burndown approach is to tank-mix glyphosate and 2,4-D because it generally keeps costs between $5 and $15 per acre and targets a broad spectrum of weed species.
Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative to learn more.
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Endnotes
- Sprague, Christy. “Getting a Start on Weed Control in the Fall.” MSU Extension, Michigan State University, 18 Sept. 2024, https://www.canr.msu.edu/news/getting-a-start-on-weed-control-in-the-fall. Accessed 13 July 2026.
- Peachey, Ed. “How to Use Herbicides Safely to Control Weeds on Farms.” OSU Extension Service, Oregon State University, 2022, https://extension.oregonstate.edu/pests-weeds-diseases/ipm/how-use-herbicides-safely-control-weeds-farms. Accessed 13 July 2026.
- Klein, Robert N., and Amit Jhala. “Weather and Burndown Herbicides.” CropWatch, University of Nebraska–Lincoln, 3 Apr. 2020, https://cropwatch.unl.edu/2018/weather-and-burndown-herbicides/. Accessed 13 July 2026.
- Hager, Aaron, Bill Johnson, and Kevin Bradley. “Adjuvants with Herbicides: When and Why They Are Needed.” Crop Protection Network, 20 May 2024, https://cropprotectionnetwork.org/publications/adjuvants-with-herbicides-when-and-why-they-are-needed. Accessed 13 July 2026.
- Curran, Bill. “Fall Burndown of Weeds and Declining Forage Stands.” Penn State Extension, Pennsylvania State University, 7 Oct. 2025, https://extension.psu.edu/fall-burndown-of-weeds-and-declining-forage-stands. Accessed 13 July 2026.
