How to Test Seed Germination Rates

Spring is only a month away, and with spring comes gardening season. Now is a good time to check the germination rates of those seeds you have stashed away in the basement—before you need to plant them!

You Will Need

  • Seeds.
  • Paper towel.
  • Large Ziploc bag.


  1. Lightly moisten a square of paper towel. (Take care that it doesn’t get soggy.)
  2. Line up 10 seeds from the same packet on the paper towel, close to the edge but not so close that they are likely to roll off.
  3. Fold the paper towel over the seeds.
  4. Carefully slide the paper towel into the Ziploc bag without dislodging the seeds.
  5. Seal the Ziploc and set it in a warm location where it won’t be disturbed.
  6. Check on the seeds daily to watch for germination and to moisten the paper towel if it starts to dry out.
  7. Once all the seeds have stopped germinating (maybe after a few days for fast-growing plants like beans or up to two weeks for slow-growing plants like carrots), count how many sprouted. You now have a germination rate.
  8. For a more accurate test, follow these instructions using 100 seeds. You will need more paper towel and a larger Ziploc bag to do this.

How to Use This Information

If your germination rate was 70% or more, you’re in luck! Your seeds are still fresh and vigorous. You should be able to plant one seed for every hole and avoid wasting seeds through needless thinning.

If your rate was more along the lines of 50% to 70%, your seeds are still quite usable. In fact, these lower rates may even be normal for some vegetables, such as carrots. However, you will want to compensate by planting two to three seeds in every hole.

If your rate was below 50%, you will have to decide if you want to bother with that particular seed packet or not. You may be able to get a little more use out of it by planting four or five seeds per hole. However, you may decide, particularly if they sprout in a tardy fashion, that it’s more worthwhile just to buy new seeds.

The Family Garden Journal