Growing flowers, vegetables, and herbs from seed is thrifty and rewarding. However, buying seeds can become addictive, and most gardeners end up with leftovers. How long do vegetable and herb seeds remain viable? There are many charts online from seed companies and university extension programs showing the possible life span of popular seeds. This information are only considered a guideline since so many factors make a difference in seed viability. There are many things that can damage seeds during storage, or at least change their longevity.

Sherry Rindels from the Iowa State University of Science and Technology has this to say:
The ideal storage condition for seeds is somewhere cool and dry. For many homeowners a capped jar in the refrigerator serves the purpose. Just looking at the seed will often give an indication of seed quality. For seeds that are usually smooth and round or plump, they will not germinate well if they are pocked or wrinkled. Peas, corn, and many other seeds are normally wrinkled but may not look as good as they should.
It is very difficult to factor in the humidity and temperature because each person has their own way of storing seeds, including everything from throwing packets in a pretty basket to sealing the seeds in labeled jars. Then we have the odd packet of seed that finds itself caught between the pages of a book, or in a magazine to mark a spot to read later. There is a simple method of testing seeds to find out if they are still viable.

Testing seeds

Fold a piece of paper towel in half, then dampen and carefully place a few of the seeds you are testing on one side. Fold the other side over the seeds and place the entire thing in a resealable plastic bag. Leave an inch or so open on the bag so the seeds have a tiny amount of access to air. Label the bag with the seed type and the date. Place the bag in a warm place such as the top of a refrigerator. Mist the paper towel if you notice it starting to dry out at any point.

Check the seeds in a week to see if they have sprouted. If they have, then you will know the packet is still viable and can be sown as the packet instructs. If not, place the paper towel and seed back into the bag and check again in a few days. Some seeds to take longer to germinate so don't give up too soon.

Chances are you may be testing more than one type of seed, so it's very important to label the plastic bags. Afterwards attach the label to the container of seeds so you know it was tested and was still viable.

Below is a list of the more common vegetables and herbs with the estimated time they will remain viable. This is simply a guideline, but will help when buying or saving seed in the future.

4-5 years
  • Tomato
  • Radishes
  • Cucumbers
  • Broccoli
  • Cauliflower
  • Cantaloupe/muskmelon
  • Beets
  • Brussels sprouts
  • Cabbage
  • Swiss chard
  • Eggplant
  • Watermelon
  • Pumpkin
  • Rutabaga
  • Winter/summer squash
  • Turnip
Greens and lettuce
  • Mache/corn salad
  • Cress
  • Endive
  • Collard greens
  • Chicory
  • Kale
  • Sorrel
  • Mustard
  • Fennel
  • Basil
  • Borage
  • Cilantro
  • Coriander
  • Nasturtium
  • Calendula
  • Dill
2-3 Years
  • Asparagus
  • Beans
  • Chinese cabbage
  • Carrot
  • Celery
  • Kohlrabi
  • Pea
  • Corn
  • Leek
  • Okra
  • Pepper
  • Caraway
  • Catnip
  • Chamomile
  • Chives
  • Fennel
  • Lavender
  • Lemon balm
  • Mint
  • Rosemary
  • Rue
  • Sage
  • Summer savory
  • Thyme
1 year or less
  • Onion
  • Parsnip
  • Salsify
  • Leek
  • Parsnip
  • Parsley
  • Angelica
  • Marjoram
  • Oregano
Image from Wikimedia Commons user Rickproser