Don't feed the weeds

What I’m going to suggest in this article is what the military would call a “preemptive strike.” In the mind of a military strategist, the thought process goes something like this: “If I already know I’m going to war, I should hit first and hit hard, giving me a better chance of winning, while losing less in the process.”

In the military version of the preemptive strike, the goal is to win the war and sustain fewer losses. In our pasture and hay ground, our desire is to win a war against weeds, while losing less plant food (which will be consumed by the weeds if they are allowed to get a start). If we win this war, all the fertilizer we apply is available to grow more forage. And, as you know, more grass equals more beef and that’s more money in your pocket on sale day.

You already know the battlegrounds. They are the same fields and pastures that had a heavy infestation of weeds last year. Summer annuals have a habit of appearing first in pasture ground sometime in May simply because there is less dense grass to impede their progress than in a hay field. Typically in a hay meadow, you will see summer annuals come on aggressively as soon as you’ve cut and baled hay, opening up the canopy for the weeds to come.

Since weeds will typically come first in pasture ground, and we don’t want to feed those weeds, this is where we should start. You’ll probably see weeds begin to emerge by mid–May. You are all geared up to bale hay in May, but Mother Nature doesn’t always give you that three-day window of good weather to cut, rake and bale. It only takes a one-day window, of clear weather, to go spray.

Choose a product with good residual, such as GrazonNext HL, Forefront HL, Grazon P+D, Cimarron or Chaparral. Talk to your local MFA or Ag Choice location about what weeds gave you trouble last year and they will recommend a herbicide that works well on your target species. Why is residual activity important? You not only kill the weeds that are present, but soil activity continues to kill weeds for 45-90 days. Most weeds won’t even emerge from the ground before they are killed. Once the hay is baled and removed from the field, you can use the same tactic on those fields.

If you haven’t taken soil tests in a while, you can pull them as you are spraying the fields. Knowing where the fertility is (or is not) in your fields is as important as knowing your bank balance. Even fescue can perform well without adequate phosphate and potash. Phosphate promotes a healthy root system and potash helps the grass regulate its precious supply of water.

Shortages in P and K during a drought is a disaster. When you are short on those nutrients, the grass has a diminished mechanism to pick up water and then can’t hang onto what little it gets. Keep the pH at 6.5–7.5 to ensure that all of your fertilizer is available to the forages you are trying to improve.

Applications for brush and tree sprouts are best made from late June through September. Check with your local MFA or Ag Choice location for help choosing the right herbicide for the species you want to remove.

Some of the most potent brush herbicides on the market are Remedy Ultra, Pasturegard HL, Surmount and Tordon 22K. Keep in mind that you need 1 or 2 years of growth on tree sprouts for them to have enough leaf surface area to absorb a dose of herbicide sufficient enough to kill the roots. After spraying sprouts, don’t brush hog six months—this provides herbicide plenty of time to travel to the root zone. The sprouts look dead after a month, but they’re not. Give them time to die completely before cutting.

Blackberries are a brush species that fall out of the normal timing for tree sprouts. My favorite recipe to control blackberry is 2.5 ounces of Chaparral per acre, plus 1 pint of Remedy Ultra per acre—with Astute at 1 quart per 100 gallons water. Spray them just after full bloom, then re-spray any blackberries that still have green foliage in early September. This two spray approach is extremely effective.

See the nearby spot-spray chart for advice on accurately mixing smaller volumes of spray. Don’t forget to use Astute or Astute Lite in these mixes. A high-quality surfactant allows herbicides to contact much more surface area on weeds, and helps the active ingredient to stay in place longer. That’s often the difference between success and failure in controlling the target weed.

It is my prayer that we get good rain and in a timely fashion. If that is the case and you use the preemptive strike, so that you don’t feed the weeds, you should see major improvements. Have you won the war? Perhaps not, but you will have gained far more grass and lost less plant food!

As always, contact me through your local MFA or Ag Choice location or via email at This email address is being protected from spambots. You need JavaScript enabled to view it. if you have questions.

David Moore is certified crop advisor and works for MFA Incorporated as a Range and pasture specialist.