Alyssa Essman, OSU Extension State Specialist, Weed Science, Christine Gelley, OSU Extension Educator ANR, Noble County, Kyle Verhoff, OSU Extension Educator ANR, Defiance County
Spring 
means rapid forage growth, but it also means rapid weed growth. Due to the variability of spring weather, there are often only a few opportunities to control emerging summer annual weeds, winter annuals missed in the fall, and biennials that are small enough to effectively control. To manage weeds before they become a problem in forages, it is important to scout and plan accordingly. Forage is a broad category, and the spring weed control plan can look very different between species and operations. The problem weeds and whether control is necessary are going to be different between permanent pasture systems and alfalfa fields, and highly dependent on the consequences of specific weeds.
In established alfalfa, the decision for weed control of some winter annuals like henbit and field pennycress will depend on the severity of the weed presence, the age of the stand, and the end purpose of the forage. If the weed pressure is high, the stand is young, or the lower forage quality of the weeds interferes with the goal of producing dairy-quality hay, the weed control treatment may be worth the associated cost. In a grazing system, it may be more pertinent to control weeds in the spring to ensure weeds that aren’t grazed don’t go to seed. Numerous weeds can be a problem in forage systems. Reference the 2024 Weed Control Guide for specific recommendations following this general overview.
