Pasture Grass Seed Mix Calculator
Calculate a pasture grass seed mix rate in pounds per acre for horse and cattle grazing, with pure live seed and bag counts.
How This Calculation Works
Bulk pounds per acre equals the target live seeds per acre divided by seeds per pound, then divided by the pure live seed fraction. A pasture mix combines species with different seed sizes, so calculate each component separately and sum the bulk weights. Dividing by 43.56 gives pounds per 1,000 square feet.
Field Calibration & Rate Reference Chart
| Species | Seeds/lb | Target seeds/ac | Bulk lb/ac |
|---|---|---|---|
| Tall fescue | 227,000 | 3,000,000 | 15 |
| Kentucky bluegrass | 1,100,000 | 1,500,000 | 2 |
| Perennial ryegrass | 227,000 | 4,000,000 | 20 |
| Bermudagrass hulled | 1,900,000 | 2,000,000 | 1 |
| Bermudagrass unhulled | 800,000 | 2,000,000 | 3 |
| Alfalfa | 200,000 | 5,000,000 | 28 |
| Winter wheat | 12,000 | 1,200,000 | 105 |
| Soybean | 2,800 | 160,000 | 63 |
| Corn | 1,400 | 34,000 | 27 |
| Cereal rye | 18,000 | 1,200,000 | 73 |
Common Questions
How much pasture grass seed per acre?
Rates run 15 to 30 pounds per acre for a mix, depending on the species and the seed tag's pure live seed. Calculate each component separately. Higher rates help in less-than-ideal seedbeds.
What is the best grass mix for horses?
Horses do well on a mix of orchardgrass, tall fescue and Kentucky bluegrass, with a legume like white clover. Avoid endophyte-infected tall fescue for broodmares. A dense sod resists trampling.
When should I seed a pasture?
Seed cool-season grasses in early fall or early spring when moisture is reliable and weeds are less competitive. Warm-season grasses go in late spring. Avoid midsummer seeding.
How long before I can graze a new pasture?
Wait until the stand is well rooted and the grasses have tillered, often 6 to 12 months depending on the species. Grazing too early damages young plants. Mow to control weeds in the meantime.