Storing Old Garden Seed

Seed catalogs seem to come earlier every year, and many gardeners already have begun to receive them. Garden seed can be expensive, and you may want to consider using seed from previous years. Seed stores best if kept in a cool, dark, dry location. Try a zip-locked plastic bag or a plastic jar such as a reused peanut butter jar to keep seed dry.

 

Seed will be viable longer if kept between 40 and 50 degrees F. Temperatures a bit lower than 40 degrees are fine as long as they are not sub-freezing. Therefore a refrigerator is a better choice than a freezer which can prove detrimental to seed longevity if there is too much moisture in the seed. Seed that has 8% or less moisture can be frozen without harm and will actually store much longer than seed stored above freezing. Seeds dried to 8% or less moisture will break instead of bending when folded.

  

Those that have a hard seed coat such as corn and beans will shatter rather than mashing when struck with a hammer.  If your seed is not dry enough for freezing, what should you do? The easiest answer is to store your seed under cool (not freezing) conditions.   Drying seeds is a rather involved process and beyond the scope of this article. However, if you would like to try, an excellent reference on an effective procedure is given in the book “Seed to Seed” by Suzanne Ashworth.

  

Crop groups vary in seed longevity. Use the following as a guide for seed stored under cool, dry conditions.

Crucifers (cabbage, cauliflower, broccoli): 4 to 5 years

Corn: 2 to 3 years
Lettuce, endive: 4 to 5 years
Spinach, beets, carrots and chard: 2 to 3 years
Cucurbits: Squash, melons (including watermelon): 4 to 5 years
Tomatoes: 4 years
Peppers: 2 years
Onion, parsley, parsnip and salsify: 1 year
  

If you are unsure of viability and have plenty of seed, there is an easy method of determining how good your seed is. Place 10 seeds on a paper towel moistened with warm water and cover with a second moistened towel. Roll up the towels and place inside a plastic bag with enough holes for air exchange but not so many that the towels dry quickly. Place the bag in a warm place such as the top of a refrigerator. Remoisten towels with warm water as needed. After the first week, check for germination.

  

Remove sprouted seed and check again after another week. Add these numbers together to determine the percent germination.

 

Farm and Garden

Penn State Extension
Franklin County
181 Franklin Farm Lane
Chambersburg, PA 17202
Telephone: 717-263-9226
http://extension.psu.edu/franklin