Testing the viability of bean seeds.| Photo by Kate Garland
With spring just around the corner, you might be browsing the seed catalogs to order your favorite fruit and vegetable strains. But don’t be so quick to buy new packages—those leftover seeds from past seasons may still be viable for planting. You can test old seeds to find out.
Chemical scarification?
For germination to occur, the embryo must be able to exchange oxygen with the outside world. The problem? The seed coats tend to harden over time, which prevents them from properly absorbing water and oxygen. While H202 can provide a chemical rough, a little more surgery is often required.
Mechanically scarifying seeds can be as simple as lightly sanding the micropile (edge) with a piece of sandpaper (being careful not to go too far), or cutting a notch out of the seed coat with a utility knife. Carefully breaking the seed coat between a pair of pliers is another method. Many veterans used to crack seeds in their teeth!
And the grass seeds?
As with other seeds, how long grass seeds remain viable depends on the seed variety and how well they are stored, says Kauth. It can remain viable for three to five years if kept cool, dry and away from rodents or insects that spoil it. Try a sturdy, tightly sealed container or basket.
What influences seed viability?
Three things will determine if your seeds are still viable.
- Age of seeds. All seeds will be viable for one to two years. After two years, germination rates will decrease for many seed types and eventually drop to zero. So, stocking up on seeds for an “emergency” isn’t a good idea, because they don’t last forever.
- The type of seed. The type of suit you have will also affect how long it will live. Some seeds like onions and corn have a short life, while others like cucumber and melon can last up to 6 years. Pelleted seed is best used within a year because the pelletizing process can shorten the lifespan of the seed.
- Seed conservation practices. Seeds stay viable much longer when you store them in a cool, dry, dark place. Reducing humidity is key. This can be as simple as storing the seeds in a sealed plastic bag with some rice or desiccant packets to absorb excess moisture. Store bags in a cool, dark place.