germination testing of seeds
GERMINATION TESTING of leftover seeds would make a good science project for grade-school kids, and it can delight and inform big people, too. If you can count to 10, you can test last year’s seeds for viability, before wasting money on unnecessary replacements.
Most are viable three to five years, but there are exceptions. Gather a couple of zipper-lock plastic bags, sheets of paper towel (one per variety being tested), small plastic labels and an indelible marker. Count out 10 seeds of each kind being tested, place them in a row on a damp paper towel, and roll it up, with the label marked with the variety name rolled inside, too.
Put the whole thing in a plastic bag (you can put a number of these rolls into one large bag) and leave it in a warm place. Check it after a few days, and again after a week, and so on, and make certain things stay moist inside.
Count the seeds that have germinated, and multiply that number by 10 to get the percentage of viability. If eight seeds are alive, your packet it approximately 80 percent viable; go ahead and use it. If only three germinated, you should re-order—or sow very heavily if you have a lot of seeds left, or only need a few plants.
Some people like to wait till later on, close to outdoor planting time, to do their germination tests, particularly with the large seeds such as peas and beans. Then, the ones that sprout are used right in the garden, so the germination test doubles as a pre-sprouting process, speeding things along and reducing the chance of failure in cold springtime soil. Even if your budget is large, try this experiment. There is nothing quite so extraordinary, nor so humbling, as the sight of a cotyledon, or seed leaf, pushing out of a seed—a botanical baby being born.
How do you plant your seeds, in rows and then transplant into the trays with holes or in the trays that are already for you to plant with soil mix and pop one seed in per hole . What is the germination results if you plug in one at a time compared to open package and sprinkle in rows?
I did this for a seed-saving presentation for our garden club. I think my book called it a rag-doll test.
I employed various methods for preparing seeds for sprouting, then used this test to see which method worked best – soak overnight, microwave, or damp paper towel. Beans soaked overnight sprouted the best and fastest.
Those things start to smell terrible if you keep them in there too long.
Margaret, what about testing old flower seeds? Do you use the same process? Have you got a table for flower seed viability like the one for vegetables?
Hi, Julie. I don’t have a chart as such, no. I see one on a website called Hill Gardens of Maine — but there is no reference for where they gathered the information, so I don’t know its accuracy (and it’s not a site I am familiar with). But yes, the process is the same and a couple of years is the general guideline.
Thanks, Margaret. Did you see the note about herb seeds lasting only a year? I think that is too pessimistic. I once scattered a half-packet of really old basil seeds in my raised bed and had enough basil for the entire neighborhood!