The best time to mow after overseeding is generally to wait around 2 to 4 weeks. This allows the new grass seedlings enough time to germinate, spread roots, and establish themselves before being cut, reducing the risk of damage. The new grass should ideally reach about 3 inches in height before the first mow, and the mower blade should be set to the highest setting to avoid stressing the young grass. Some experts say mowing as early as 7 to 10 days can work but waiting longer is safer. Timing can vary based on grass type, climate, and soil conditions. For example, ryegrass may be ready to mow in about 2 weeks, while slower-growing types like Kentucky bluegrass need more time. Warmer climates or summer overseeding might require closer to 3 weeks or more. Consistent watering is important before mowing to encourage healthy root growth. In short:

• Wait 2 to 4 weeks after overseeding before mowing
• Mow only when grass reaches about 3 inches tall
• Use the highest mower blade setting
• Adjust for grass type and climate conditions

This cautious approach helps ensure the best results from overseeding and avoids uprooting new seedlings or stunting growth.