Summer annual grasses in turf can be managed with all of the following practices except:

• A. Aerating the turf after applying a pre-emergent herbicide
• B. Regular mowing
• C. Proper fertilization
• D. Properly-timed application of post-emergence herbicide

Answer: (D)

Summer annual grasses in turf are best controlled by preventing their germination and keeping the turf dense and vigorous so it outcompetes weeds. The most effective approach combines a pre-emergent herbicide applied before seed germination with cultural practices that enhance turf health. Regular mowing helps maintain a dense turf canopy, which screens and reduces the chance for weed establishment. Proper fertilization supports vigorous growth, making the turf more competitive against weeds.

Aerating after applying a pre-emergent herbicide is a compatible part of turf maintenance when done thoughtfully. It improves root development and soil health, helping the stand compete and not typically undermining the pre-emergent barrier if managed correctly.

Post-emergence herbicides, while they exist, are not as reliable as a primary strategy for summer annual grasses in a turf setting. These weeds grow rapidly, and timing can be tricky; post-emergence products can be less effective and may risk injury to desirable turf if not applied precisely. That’s why this method is considered the exception to the other practices listed.