By Darren Hefty

Marestail, dandelion, and other troublesome winter annuals, biennials, and perennials can be eliminated for your next crop season yet this fall! Below are some excellent options to get the job done. There are also some products and situations you want to avoid. Here’s a rundown on both.


Stop your combines on a fall afternoon when the air temperature is over 70 degrees and the wind is relatively calm. Spray 1 quart of Banvel or Clarity per acre, and you will wipe out any and all marestail issues. This same strategy works well for dandelions and most other problem no-till/strip-till weeds, too. You don’t need to add anything else in the spray tank in most cases. Just put the Banvel or Clarity in and enjoy your results next spring when everyone else is fighting huge Roundup-resistant weeds. As always, check the label for rotational restrictions, but if next spring you are planting corn or Xtend soybeans, you will have zero issues.


There are some excellent weed killers that fall (pun intended) into late season burndown programs like Elevore, Distinct, and Autumn, just to name a few. Both the old standby products and some of these new ones will work well at this time. Speak with your agronomist about what fits your weed spectrum.


If you are in the northern U.S., residuals aren’t as necessary as they are in the south. In the north, your money is best spent on a really high rate of dicamba (as mentioned above) or 2,4-D in situations where you need to take out winter annuals. However, I still love residual herbicide use in the fall in no-till and reduced tillage situations. Products like Valor are excellent on most Roundup-resistant and ALS-resistant weeds. Farmers who use residuals in the fall report a significant decrease in weed pressure in the spring. I understand you may not have sprayed a fall residual in the past, but I’d encourage you in heavier weed pressure situations to give it a try this fall on a portion of your acres, as I believe the return on investment will definitely be there.


If you have perennial weeds in your lawn, pasture, non-cropland, or even in your fields, fall can be a great time to control them as long as you’re out there before the first hard, killing frost. Products like Milestone, Tordon, and Roundup can move down into the root system and kill the weed for good, provided the plant is still functioning normally and is receptive to herbicide intake. If you have a perennial weed and your crop rotation allows, use the full recommended rate of these products soon.


Avoid spraying expensive products that require translocation in the plant after frost has happened in your area or when the weeds are completely hardened off due to extended drought. You won’t be able to get the products into the plants and will likely be wasting some or all of your money.
Annual weeds that have already gone to seed are likely in your fields and non-crop areas. Killing them now is simply a revenge kill in most cases, with virtually no return on investment. The damage is already done.


  1. If you’ve already had a hard frost, your potential weed control from a herbicide application will be reduced greatly.
  2. If you haven’t had a hard frost, this is a great time to wipe out weeds that normally survive the winter.
  3. Revenge kill on annual weeds that have already gone to seed doesn’t help with much other than harvestability. Those weeds will be dead soon when it freezes hard.