We’re in the “Dog Days of Summer” and summer weeds are beginning to bloom in pastures across the county. This often generates a number of calls on how to effectively control them. Keep in mind that herbicides only work on juvenile stages of weeds, which translates for most to when they’re below 18”. Once the plant is at mature height, even the best herbicides won’t be effective.
One example of a weed we’re seeing out there this month is pigweed, which is a summer annual. Pastora, Remedy (triclopyr) and Weedmaster are excellent control options for pigweed, but only if you time it right. For most producers, it’s already seeding out, so the sprays won’t be very effective. At this point mowing might be your only option. Typically pigweed emerges from seed in our area in late May and early June. June 1st is an excellent time to scout and spray.
We’re also seeing a lot of dogfennel. Dogfennel is a perennial weed that is 3-4’ tall in most areas at this point. Your battle right now is to try to mow it down before it goes to seed. Typically dogfennel emerges from seed in April. If we scout effectively we can spray it just before hay season with something like Milestone, Banvel, Surmount, or Remedy when the plants are 18″ or smaller. If you’re lucky, you might be able to time your control option for pigweed and dogfennel into one spray application in late May, or early June.
Thistle is another common weed that represents a totally different category of weeds, it’s a biennial. This means it germinates from seed and remains in a rosette stage for one year, before blooming the following year. Right now we’re seeing a lot of purple flowers and a lot of white seed heads across our fields and pastures, as our window for effective control is long past. Typically it’s best to time your herbicide application for thistle in the fall. I like to recommend folks scout for thistle, chickweed, buttercup, and henbit seedlings before making that fall application. For the most part you can eliminate a large number of weeds with one application in the fall. ForeFront, Grazon Next, Crossbow or 2-4D make effective options.
Knowing the life cycle of your weeds helps you make timely decisions for control. You also need to keep in mind that many other cultural practices also come into play. Maintaining a healthy stand of grass is actually the most effective means of preventing weed problems. It’s not the chicken litter bringing you the weeds, and it’s most likely not blowing in from the neighbors pasture. Weeds take advantage of opportunities you’ve left them. The best way to eliminate opportunities is to soil test to ensure your soil pH is at the right level, make sure to fertilize according to soil test recommendations at the right time of year, and do your best to prevent overgrazing.
If your stand is getting thin, it might be time to think about sprigging bermuda or overseeding with fescue. Typically we overseed fescue in September, and sprig bermuda in May. If you’re tempted to try wheat, rye or ryegrass, think about planting them in a separate paddock as a rotational grazing tool. When mixed with fescue, these 3 cool season grasses often smother the fescue, and then die out in summer, leaving the perfect place for weeds to take hold. When grown in pure stands they provide unbeatable forage for cattle during some critical grazing periods. Timing your cultural practices is your best tool for growing top quality forages and hay, instead of pesky weeds.
If you’d like more information on managing pastures and hay fields, check out our website at: https://www.georgiaforages.com/ and https://www.caes.uga.edu/departments/ent/pest-management/Commercial-Perennial-Grasses.pdf.
About the Author:
Steven Patrick is the UGA Extension Agent for the Northeast District. His office is based in Habersham County.
