Answer: Select the type of grass you plant based on your region and climate. A mixture of Kentucky bluegrass, fine-leaf fescues, and perennial ryegrass will probably work best for you.
The weight of seed you'll need depends upon the mixture of these grasses you use. For instance, if you use a higher proportion of Kentucky bluegrass you'll need fewer pounds of seed. Since two-thirds of a half acre is about 15,000 square feet, I estimate you'll need 60 to 80 pounds of seed.
For more information, see the <a href="http://www.extension.umn.edu/distribution/horticulture/DG0488.html"target="new">Minnesota Estension Service</a>.
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