What Makes a Seed "Bad"?
Does seed go bad? A question we've heard a lot working in this business. It's somewhat of a complicated answer--but here goes . . .
If what you mean by "go bad" is spoil, then no, it does not go bad. A common misconception is that with time seed naturally spoils, aka "goes bad". But it simply is not true--seeds are designed to stand the test of time and to ensure growth when the right conditions are met. There is nothing in the seed itself that will spoil. There are several factors that can go into damaging or deteriorating seed that makes it harder to germinate, such as seed-harvesting techniques, handling practices, and storage methods. If you're buying high-germ seeds, storing them right, and handling them with care, they should last for years to come.
A type of ancient wheat seed was found in ancient Egypt in the late 1800's, and after being sealed-off for hundreds of years, the seeds sprouted just fine. "Fifteen stems . . . sprung from a single seed," T.E. Thorpe said in an 1857 issue of Harper's New Monthly Magazine article after testing centuries-old grain. It just goes to show how tenacious seeds are when given the right circumstances for storage. Just remember: cool, dry, and dark--the elements needed to long seed storage.
The most important thing to consider when storing your seeds is the humidity levels in your area of the country. Granted, the west lends itself to the storage of seed because of low levels of humidity, making seed storage ideal for us here in Salt Lake City. So, if you are at lower elevations where high humidity is more common, a few extra steps may be required to cultivate a dry place for your seeds. The quickest and easiest solution is to double-seal your seeds in two ziplock bags and place in the freezer--if you have bulk seeds a box freezer may be required. If you have a cellar or basement, it may be useful to look into ways to dehumidify that specific area. Understanding humidity control, allows you to create the environment that these seeds are designed to hibernate in for years to come.
Another misconception is that seeds will inevitably deteriorate after a five year period of storage--which, again, simply isn't true. If germ problems arise with your stored seed, it is either a result of inappropriate handling or storage.By handling, we refer to missteps in the preparatory, planting, and/or watering stage of growing seeds, applicable to all growing methods. Some of these missteps can be using mechanical seeders that can damage the seeds, soaking seeds too long causing the seeds to drown, watering too much or not enough as seeds germinate, etc.. Even moving sealed buckets of seed from one storage area to another can be problematic when not handling the buckets with care. These factors can lead to seed failure but that doesn't mean the seed was "bad" or has "gone bad".
The term "bad seed" gets thrown around a lot, leading to much misunderstanding as we've pointed out. In this case "bad seed" can refer to invasive species of plants that can harm and/or disrupt the ecosystem to which they are not native. A good example of this is purple loosetrife. Introduced to the United States in the 1800's for decorative and medicinal uses, it has had a substantial impact since then becoming a dominant plant in wetlands. So seeds can be "bad" when referring to their effect on an ecosystem--a very different meaning from "going bad" in terms of spoiling. Nevertheless, the distinction is worth noting and considering when assessing the status of your seeds.
Another example: Say, you want to plant peppermint in your garden this spring that has been stored in a cool dry place for a few years. You test it and germination is up to standard. So, it is ready for planting; however, peppermint can quickly take over a garden if planted in the ground with other herbs, vegetables, and flowers. Its invasive nature can disrupt the mini ecosystem of your garden, making it "bad seed" for that application. But, no worries! Just plant it in a container in your garden. Problem solved.