Germination rate is the term used to describe the percentage of seed from a particular plant species that will emerge when given the right conditions. The germination rate is important information to know ahead of time and helps the home gardener or farmer determine how thickly or thinly any given seed needs to be sown.
Germination rate is a consideration whenever you are ordering seeds from a catalog or if you have leftover seeds from previous years and you want to use them.
Seeds will not last indefinitely and some seeds are more time sensitive than others. Keeping all seed cool and dry will go a long way in help to preserve its viability.
Most vegetable seeds will last about 3 years and some can last as long as 6 years.
Corn, onions, leeks, chives, green peppers, parsley and sometimes parsnip seeds are seeds that don’t store well and should be tested every year before planting if they were held over from the prior year.
Beans, peas, beets, cabbage, Brussels sprouts, broccoli, kale, carrots, eggplant, squash, pumpkins, tomatoes, basil, sage, rue, borage, anise, dill, oregano and most herbs have a seed life of between 3 – 4 years.
Spinach, lettuce, cucumbers and most melons have a seed life of about 5 and sometimes 6 years.
For most common garden vegetables or flowers, seed germination rate is easy to test at home. It’s always a good idea to test germination rate if the seed is much older than 2 years old or wasn’t stored under ideal conditions.
The way that I test seed for viability is by first counting out 20 seeds.
I then place the seeds on top of small plate that has been lined with a wet paper towel or inside a paper towel where a little bit of potting soil has been sprinkled.
The paper towel or lined plate is then placed inside a plastic bag and sealed. The sealed test seeds are left on top of the refrigerator or in a warm room for about a week or 10 days depending upon the type of seed.
Some seeds take longer than others to germinate and some seeds require total darkness for germination.
Once the seeds begin to germinate I count seeds to find the percentage. By using 20 seeds for testing I’m able to get the percentage in 5% increments.
The Early Butler corn seed pictured above tested out at 90% – maybe 95% . I wasn’t going to wait any longer for one kernel that looked like it was maybe beginning to sprout.
To evaluate germination rates the following percentages are helpful:
100% – Great! You can’t do any better than that.
90% – Excellent. You can count on the planting rate information supplied with the seed.
80% – Good. You shouldn’t have too many problems as long as environmental conditions are favorable.
70% to 60% – Poor. If you want to use the seed better sow it thick.
50% or Less – You might not want to waste your time. Throw it out and buy fresh seed unless it is very rare.