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When should you overseed?
Use the calendar as a starting point, then confirm with soil temperature and moisture. The seed quantity comes from your grass type and area.
Overseeding window
Window has closed
Next window: Aug 15, 2027 – Sep 30, 2027.
Days until window
286days
Seed rate
5lb / 1,000 sq ft
Seed for this lawn
25lb
Window ends
Sep 30, 2027
Typical windows
Cool-season lawns: mid-August through September, when the soil is still warm but the air is cooling. Transition zone: September into mid-October. Warm-season grasses: late spring to early summer, when soil is reliably warm.
These are planning windows, not guarantees. A hot, dry September is different from a cool, wet one. Soil temperature at 2–4 inches and consistent moisture matter more than the date on the calendar.
Seed quantity
The planner uses a common overseeding rate for the selected grass. Follow the seed label if it gives a rate for your cultivar or situation. If you are repairing bare spots, loosen the surface and keep the patch moist; seed sitting on compacted soil is bird food.
After seeding
Keep the top inch of soil moist until germination, then reduce frequency and water deeper. Avoid pre-emergent herbicides that are labelled to prevent the grass you are trying to establish. Read the label and check the interval.
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