Simple Seed Germination Test

Is that milk in the back of the fridge still good? How about that unopened packet of tomato seeds from last year?

Just like food from the grocery store, seed packets come labeled with a “packed on” or “sow by” date.   Seed companies put these dates on the packets to guarantee that a certain percentage of seed (usually above 90%) will be viable (able to grow, or germinate from a seed into a plant).  Just like food from the grocery store, some expired seeds are still perfectly good- but the longer you wait, the less appealing they may become.

Here is a simple way to test if that packet of seeds you forgot about last season are still good enough to plant from High Mowing Seeds :


Paper towel 

Ziploc bag



Permanent Marker


  1. Use a double thick paper towel.  Moisten with water and fold in half.
  2. Open paper towel and place a minimum of 10 seeds on one side of towel.
  3. Fold paper towel over covering seeds completely.
  4. Place paper towel in plastic bag, or on plate covered with plastic.  It is ok to roll or fold paper towel to fit if necessary.  Do not air seal bag shut as you need some air for healthy germination.
  5. Put bag in a warm spot (for example, on top of your fridge).
  6. Check daily to make sure towel does not dry out.
  7. Most seeds will germinate within 3-10 days.*
  8. Check seeds every few days, and monitor seed quality and germination rate.  Healthy seeds have uniform germination and will not have any fungal or bacterial growth on outside of seed coat.
  9. Now, here comes the MATH: Just multiply the number of germinated seeds by 10 to get the percent viability rate.  If 9 out of 10 seeds have germinated, you have a germination rate of 90%,  8 out of 10 is 80% and so on.
  10. If your germination rate is less than 60%, consider buying new seeds or sowing your seeds extra thickly to compensate for the low germination rate.

*Note:  Some flowers and herbs may take longer and have special germination requirements (for example, some seeds need to “scarified” by scratching with sandpaper, or “stratified” by being put in the freezer to mimic winter conditions.)  .  There is a great deal of specific germination info listed online –  do a simple Google search for “germination requirements for ___”

How can I improve the shelf life of my seeds?

You can improve the shelf life of your seeds by storing them in a cool, dry place in an airtight container. Some seed savers add grains of rice to absorb moisture.  Humidity is the enemy!!

What if I need to get new seeds?

VINES can offer seeds (as they are available) to community garden members free of charge by contacting  These seeds are donated to us by seed companies and gardening stores and may be a year or two old. To purchase new seeds, we recommend companies such as Johnny’s Seeds or High Mowing Seeds.  For hard to find or heirloom seeds, check out Baker Creek Heirloom Seeds.

How Long Different Seeds Will Last Under Proper Storage Conditions

Here is a brief list of how long different seeds are viable. Check out this High Mowing See Viability Chart for additional information.


  • Beans, 2 to 4 years
  • Carrots, 3 to 4 years
  • Sweet Corn, 1 to 3 years
  • Cucumber, 3 to 6 years
  • Lettuce, 1 to 6 years
  • Melon, 3 to 6 years
  • Peas, 2 to 4 years
  • Peppers, 2 to 5 years
  • Pumpkins, 4 to 6 years
  • Tomato, 3 to 7 years


  • Basil, 3 to 5 years
  • Chives, 1 to 3 years
  • Cilantro and Dill, 1 to 4 years
  • Oregano, 4 years
  • Parsley, Rosemary, and Thyme, 1 to 4 years
  • Sage, 1 to 3 years