Is Your Seed Dead or Alive – A Seed Viability Test

Whether you are planting a winter or upcoming spring crop, re-seeding or enhancing a stand of Conservation Reserve Program (CRP) or State Acres for Wildlife Enhancement (SAFE), or simply interested in seeing if a winter, spring or possible summer cover crop planting will help the overall health of your soil, it is important to make sure the seed you plan to use is viable.

A “Seed Tag” usually accompanies seed purchased from seed companies. This tag tells the buyer several things: 1) what variety and species is in the bag, 2) a lot number which tracks where the seed was produced, and 3) information such as the percent purity, percent inert material, percent weed seed, percent noxious weed seed and percent total germination.

Unfortunately, not all seed comes with a tag. Any seed that has been set aside from harvest to be planted for next year’s crop will not have this information. One- or two-year-old seed should be fine to plant, but what if a producer had some seed from 10+ years ago that they wanted to use?

Fortunately, there is a simple way to test seed viability.

You will need:

  • A petri dish (plastic, shallow, flat, clear dish) or a ziplock bag
  • A lid for the petri dish
  • A paper towel
  • Plastic wrap
Then, you’ll follow these five simple steps:

  1. Moisten a piece of paper towel with water and place it in the petri dish;
  2. Evenly place 10 or more seeds on the paper towel. You may want to fold the towel over the seeds so both sides of the seeds are moist;
  3. Place the lid on the dish and wrap tightly with plastic wrap;
  4. Place in a warm environment (i.e., kitchen counter); and
  5. Wait for 7 to 10 days, then check the dish for seeds that have visibly germinated (i.e., sprouted) and count them.
The percentage of germinating seed also known as pure live seed (PLS) will give you a fairly good idea how that same seed should perform when planted provided the seed receives adequate moisture. Adjust seeding rates based on the percentage of germinating the seed.

Example:

Species: Eltan WW

PLS: 80%
Desired seeding rate: 12 seeds/ft row or 50 lbs. /A on 12-inch spacing (St. Andrews Variety Trial Seeding Rate)

The seeding rate of bulk seed: 50/0.80 = 55.5 pounds of bulk seed

Therefore, you will need an additional 5.5 lbs/acre of seed to reach either the desired 12 seeds/ft row or 50 lbs/acre based on a PLS of 80%.

For help with converting lbs/acre to seeds/ft row, lbs/acre to seeds/acre or vice versa for both, please visit our Crop Tools & Calculators page and check out the Seeding Rate Converter calculator.


For questions or comments, contact Dale Whaley by email at dwhaley@wsu.edu or by phone at 509-745-8531.
Washington State University