How to Plant Old Grass Seed


Many of us have found an old bag or box of grass seed in the back of the shelf of cabinet in the garage and wondered if it would grow. The answer, of course, is "Maybe." Depending on how it has been kept and how it is planted, grass seed can remain viable for years. Seed grows to maturity with a set of biological preconditions that "program" it to germinate only under conditions that allow the plant to survive. As each year passes, only the strongest seeds survive.

Step 1

Test seeds for viability by counting out 100 seeds and scattering them in potting soil in an empty milk carton or other container. Put your "test batch" in a sunny window and keep it moist, not wet, for several weeks until the grass is up. Count the number of blades to determine the percentage of germination you can expect.

Step 2

Top-dress your lawn bed with compost mixed with an equal part of humus or manure. Work the top dressing in well to create an optimally fertile bed.

Step 3

Remove all rocks and weeds. Break up clumps of dirt so that the soil is fine enough to rake flat. Level the lawn bed as you go so that water does not stand in puddles.

Step 4

Scatter seed in early fall according to the corrected germination rate. For example; if the original germination rate was 97 percent and the actual germination rate is 50 percent, spread the seed at twice the rate as normal. Water gently but well so that the seed settles into the soil.

Step 5

Keep the seed moist until germination. Water young grass in the early morning to minimize the chance of evaporation or fungus due to water sitting overnight. Wait to mow until the grass reaches 3-4 inches tall and remove only a third of the leaf.

Tips and Warnings

  • Perennial grass seed types lose viability by percentages each year but annual rye grass, which is included in many mixes for "quick cover" is remarkably long-lived. If you have an old mixture with annual rye grass in it, you may have a worthless sack of rye.

Things You'll Need

  • Milk carton and potting mix
  • Spray bottle
  • Garden spade
  • Garden rake
  • Compost and humus or manure
  • Grass seed
  • Water
  • Sprinkler or irrigation system


  • University of Illinois Urban Extension: Saving Seeds
  • The Helpful Gardener: 20 Year-Old Grass Seed

Who Can Help

  • Oregon State University Seed Laboratory:Storing Seeds
  • The Garden Counselor: Understanding Grass Seed Germination
Keywords: grass seed, old seed, planting grass

About this Author

Chicago native Laura Reynolds has been writing for 40 years. She attended American University (D.C.), Northern Illinois University and University of Illinois Chicago and has a B.S. in communications (theater). Originally a secondary school communications and history teacher, she's written one book and edited several others. She has 30 years of experience as a local official, including service as a municipal judge.