By: Ty Torrance

Weed control in pastures and hayfields can be a challenge. First of all, let’s define what a weed is in a pasture and/or hayfield. By definition a weed is any plant out of place.  For example, if you have bahia grass in a bermudagrass hayfield then the bahia is considered a weed, even though you may have planted a beautiful bahia grass pasture right across the fence.  With that in mind we want to focus on the weeds that are really taking away from production. In other words, there are some plants that we can live with in a given situation and some we can’t live with in another and it’s those we can’t live with that we should focus our attention on.

Proper identification of weeds is important and your county extension agent is a good source to turn to for id. In most situations, it is easy to bring a sample plant into the office to be identified.  Other times we may have to make a field visit to check out the variety of weeds you are dealing with. (What’s a good sample? Pull up the whole plant if possible with leaves, stems, roots, flowers and fruit or seeds attached. Bring it in while it’s fresh and preferably not after it’s been riding on the dash of your pickup for three days in 100º weather.) Be ready to answer some questions: (Is it all over the field or is it localized in one spot? Is it new to your fields or has it been there for a while? Is it small or large?).

Why is proper identification so important? Some plants are poisonous to livestock and we certainly want to get rid of them; another good reason is because different weeds require different management techniques. It may be possible to control some weeds by grazing, mowing or burning or it may require specific herbicides for control. There is no silver bullet herbicide that will control every single species of weed in one shot. If you choose the wrong option, you may be wasting your money and your time.

Timing of control is critical.  Many weed species must be controlled at a certain stage of growth to ensure a good kill.  Some weeds need to be killed before they mature and produce seed. Many weeds are best sprayed in spring either just before flowering or when flowering. If you wait too late to control some annual and biennial weeds after they have gone to seed, you will have the same problem next year when those seed germinate. There are some perennial weeds that need a full year’s growth without mowing and/or burning to increase your chances of control (Example: blackberries). Some weeds may be controlled better by spraying in the fall. Again, timing can be critical. 

Sometimes we can spot spray and get good results, especially if the weeds are localized in one area. Size can also be an issue simply because big weeds are usually harder to kill.

If you wait until the weeds are hitting the hood of the tractor it is probably too late for a single spray fix. Take a little time and plan in advance for your best weed control options. Make sure you have properly identified the weeds that you want to control and that you are timely in your control methods. Plan your weed control program a year in advance and you will increase your chances of success and maybe save yourself some time and money.

For more information about these or other subjects contact Decatur County Cooperative Extension office. (229) 248-3033.