Garden Guide
New Lawn vs Overseeding
The same grass seed can use very different rates depending on whether you are covering bare soil or thickening existing turf.
Table of Contents
Main Difference
A new lawn seed rate is for bare soil. An overseeding rate is for an existing lawn with grass already in place. Use the Lawn Seed Calculator and choose the job type that matches the area.
| Situation | Use this rate | Why |
|---|---|---|
| Bare soil after grading | New lawn | Seed must cover the full area |
| Thin lawn with visible grass | Overseeding | Existing grass fills part of the canopy |
| Dead patches larger than a dinner plate | Patch or new lawn rate | Bare spots need heavier coverage |
| Annual fall thickening | Overseeding | Goal is density, not full establishment |
Example
A 1,000 square foot bare area might need 7 lb of tall fescue. The same 1,000 square feet as overseeding might need only 3 to 4 lb.
How to Decide
- If more than half the soil is bare, use the new lawn rate.
- If grass is present but thin, use the overseeding rate.
- For mixed lawns, calculate bare patches separately.
- Water lightly and often until germination.
FAQ
New Lawn vs Overseeding FAQ
Is overseeding the same as planting a new lawn?
No. Overseeding adds seed to existing turf, while a new lawn starts from bare soil.
Why is the overseeding rate lower?
Existing grass already occupies part of the area, so less seed is needed.
Can I use a new lawn rate when overseeding?
It is usually wasteful and can crowd seedlings.
How should I handle bare patches?
Use the new lawn or patch rate for bare spots, even if the rest of the yard is overseeded.
Should I fertilize when overseeding?
A starter fertilizer can help, but base the amount on the product label and local rules.
Which calculator handles both cases?
The Lawn Seed Calculator supports new lawn and overseeding estimates.