The Shelf Life of Seeds

Winter is a great time to dream about spring. So every year about this time seed catalogs start pouring in, I get my seeds out of my refrigerator crisper drawer and see what I have, what I need, and what I still have from a few years back.  I always wonder about the date on the seed package and if the leftover seeds from years past will still germinate.  For some reason the date always reminds me of an expiration date, like the old seeds have gone bad or something.  But that is just silly.

Seeds are covered in an outer coating called the testa. This coating helps to protect the inner embryo and keep the seed dormant until the proper conditions arise for germination.  Most seeds are viable for many years, however as the years pass the rate of germination will decline. Keep in mind that making sure seeds are kept dry during storage is important. Moisture causes seeds to rot.

Here are four ways to easily store your seeds, each increasing the length of viability:

• A simple, inexpensive but efficient storage container can be a canning glass jar with an airtight lid.
• Storing seeds at low temperatures (in a refrigerator or freezer) also prolongs their viability and in fact allows them to be kept without significant germination loss.
• Seeds that are hermetically stored (without oxygen) can stay viable for many extra years, even at a stable temperature of 70 degrees.
• Hermetically stored seeds also kept at low temperatures can expect to be viable indefinitely. The USDA states, “Each 5.6^oC. (10.08^oF) drop in temperature doubles the storage life of the seeds”.

The following is a list of the AVERAGE number of years some common seeds can sit around, without being chilled or hermetically sealed, and still have optimum germination rates (around 90%). Even after years have passed, many seeds will still be viable for many more, just not at 90%.

 

Alfalfa -4 years

Arugula -5 years

Asparagus – 3 years

Barley-2 years

Beans – 3 years

Beets – 4 years

Broccoli – 5 years

Brussels Sprouts – 4 years

Buckwheat -2 years

Cabbage – 4 years

Carrots – 3 years

Cauliflower – 4 years

Celeriac – 3 years

Celery – 3 years

Chard, Swiss chard – 4 years

Chicory – 4 years

Chinese Cabbage – 3 years

Clover – 4 years

Collards – 5 years

Corn – 2 years

Corn Salad- (mache) – 5 years

Cress – 5 years

Cucumbers – 5 years

Eggplant – 4 years

Endive – 5 years

Flax – 3 years

Hemp -5 years

Kale – 4 years

Kohlrabi – 3 years

Leeks – 2 years

Lettuce – 6 years

Muskmelon – 5 years

Oats -2 years

Okra – 2 years

Onions – 1 year

Parsnips – 1 year

Peas – 3 years

Peppers – 2 years

Popcorn – 8 years

Radishes – 5 years

Rice – 4 years

Rutabagas – 4 years

Salsify – 1 year

Scorzonera – 2 years

Sorrel – 4 years

Southern Peas – 3 years

Soy Bean – 5 years

Spinach – 3 years

Squash & Pumpkins – 4 years

Sunflowers – 2 years

Tomatoes – 4 years

Turnips – 4 years

Watermelon – 4 years

Wheat – 2 years

Written by Emma O’Connell, Founder of Pick-A-Pepper.com

References:

http://www.ipm.iastate.edu/ipm/hortnews/1995/3-3-1995/seedv.html

http://www.sproutpeople.com/grow/storage.html

photo:

http://www.kitchenwiccan.com/needful-thingscuriosity-shop/aldoras-emporium/