How to Calculate the Amount of Grass Seed Per Acre
When dealing with lawns or other small areas, it is not big deal to overestimate and spread more seed than necessary. However, when dealing with the high costs associated with seeding acreage, it is important to know exactly how much grass seed you will need per acre. The amount you will need to seed an acre largely depends on the type of grass you are seeding and the time of year in which you are seeding your land.
Determine the variety of grass seed that you have. Some commercial grass seeds contain only one variety, but most are a blend of three to four varieties. By law, all seed producers in the United States must label their packaging with the variety(ies) contained within. If you received your grass seed from some other source, contact that source to discover exactly what variety of grass seed you have. Most seed packages will also give you the recommended amount to plant per square foot/yard, which is also helpful.
Determine the application rate for the variety(ies) of grass that you have. Most commercial grass seed in the United States will list the application rates on the packaging. Grass seed application rates range between 40 pounds per acre and 200 pounds per acre depending on the variety or varieties of the grass in the bag and their germination rates. The application rate is often given per square yard or per 1,000 square feet. One acre has 43,560 square feet. To quantify the amount needed for an acre, multiply that number by 43.560.
Factor in the season. Ideally, warm season grasses like fescue, ryegrass, bluegrass and bentgrass should be planted in late spring or early summer. Cool season grasses like bahaiagrass, bermuda, centipede and buffalograss should be planted in early fall. However, sometimes it is necessary to plant out of season. However, when planting off season, you will want to increase the amount of grass that you seed by roughly one quarter as germination rates and seedling survival will be less.
Don't buy grass seed that is nine months older than its test date. Its germination rate will be much lower than that listed on the bag.