How to Read a Grass Seed Label

Grass seed labels are strictly governed by law which dictates how information must be displayed. This information gives you what you need to pick the highest quality grass seed, as well as whether it is the variety that you selected.

Once you understand the implications of the information on a label, you can make the best choice. Here are the most important things to know about a grass seed label.

Directions for use

Most grass seed mixes give you suggested amounts for seeding a new lawn and reseeding an old lawn. It should give you an idea of coverage, such as a statement that reads “enough seed for 1,000 square feet of new lawn or 2,000 square feet for reseeding,” and it may give you the spreader setting to use. This ensures you can plan for your lawn, and the correct spreader setting.

The amount of seed you’ll need depends on the seed size and growth habits as well as your square footage.


Each seed label lists the percentage of different grass species and varieties that are contained in each bag. The percentage of each grass species will vary from blend to blend to give the best results for the particular problem or light condition that you are looking to address. For example, a shady blend will contain at least 45-50% fine fescue, because that species performs better in the shade than others.

Germination percentage

This lets you know what proportion of which seed will germinate on ideal conditions, as of the test date. Multiply the germination percentage by the percent of the grass type to figure out what percentage of each type could potentially grow. It’s not on the label, but you can determine it before you buy to see if the mix proportion is what you want.

Using the same example of 60% Kentucky bluegrass and 40% fine fescue. Say the germination percentage of bluegrass is 80%. Multiply .60 and .80 to determine a 48 percent potential for bluegrass. If the red-fescue percentage is 90 percent, you can calcuate a 36 percent red fescue by weight. As germination percentage goes down, you’re essentially purchasing less seed.

If you purchase a straight mix, the label lists percentage of purity. This has the same essential meaning as the percentages of grass types within a mixture. A box of straight bluegrass should be at least 95 percent pure. Multiply purity by germination percentage to find the viable seed percentage — and therefore, the value of the seed.

Other crop and weed seed

Some of the most serious weed types may not be listed. Bromegrass, orchardgrass and timothy — all commercial grass crops — are serious weeds in some lawns because they invade or overseed nearby grasses. Even a few seeds could get out of control in some lawns.

The percentage of weed seeds in a package of lawn seed can represent a few harmless weeds with large seeds or many serious weeds with small seeds. Check labels carefully and go with reputable brands  to ensure you’re getting the best seed with the least chance of weeds. Many grass seeds are guaranteed to be 99.99% weed free. The difference between 99.99% weed free and a blend with less than this level of purity can be up to 10,000 more weed seeds in the inferior product.

Noxious weeds

They are what they sound like — weeds that can be hard to kill but deadly to your patience once they’re in your lawn. Many are aggressive spreaders by runners and bulbs as well as seed. What defines a noxious weed varies by state, and there’s a national list, too. Noxious weeds must be named and numbered per ounce. There should be none in a high-quality seed mixture, and you should never buy a bag of grass seed that contains noxious weeds since they are very difficult to control.

While percentages are great ways to determine value, they can be tough to calculate in the aisle of your local store, sp keep this tip in mind: Simply compare germination percentages, crop- and weed-seed percentages and any noxious weeds for a good approximation of value.