When are preemergent herbicides applied for summer annuals?

When are preemergent herbicides applied for summer annuals?

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

Answer: (A)

Preemergent herbicides must be in the soil before weed seeds begin to germinate. For summer annuals, seeds typically germinate as soil warms in late spring to early summer. Applying the product in spring puts the protective barrier in place just as seeds would start to sprout, preventing those weeds from emerging. If you wait until summer, germination has often already started or occurred, so the herbicide won’t stop the established seedlings. Always follow the label for the exact timing based on your product and climate, and water in as needed to move the herbicide into the soil.

Preemergent herbicides must be in the soil before weed seeds begin to germinate. For summer annuals, seeds typically germinate as soil warms in late spring to early summer. Applying the product in spring puts the protective barrier in place just as seeds would start to sprout, preventing those weeds from emerging. If you wait until summer, germination has often already started or occurred, so the herbicide won’t stop the established seedlings. Always follow the label for the exact timing based on your product and climate, and water in as needed to move the herbicide into the soil.