Biennials should be treated when?

• A. Springtime
• B. Summer
• C. Fall
• D. Winter

Answer: (A)

Biennials have a two-year life cycle: they spend the first year as a rosette and overwinter, then in the second year they bolt and set seed. The best time to treat is in spring, when these plants are actively growing but before they bolt and produce seeds. At this stage, systemic herbicides move through the plant more effectively to reach the root and crown, giving stronger control and helping prevent flowering and seed spread. Treating later in the season or when dormant (fall, winter) is less effective because the plant’s growth slows and chemical movement within the plant is limited.