It’s not too early to test seeds

By Marilyn McKinley

OSU Ext. master gardener volunteer

Q. How soon should I test my saved seeds for germination? How soon will I need to start plants for spring? And, how?

Carol from Youngstown

A. No matter the seed you intend to use, from tomatoes to vegetables to showy annuals, and beyond – act now! Don’t be disappointed, test those seeds for germination before planting. Another thing to consider, be sure the seeds were not from a hybrid plant. If they were, you will likely not get a flower or fruit that is like the one from the previous year.

Here’s how I check to see if they are viable. (Seed viability = how many seeds are alive and given the appropriate conditions will reproduce themselves). It’s easy and will save time and possible disappointment later. Viability rates vary widely.

1. Place 10 seeds an even distance apart on a damp paper towel. Roll up the towel and place it in a plastic bag. Label the bag.

2. Leave the bag in a warm spot in the kitchen for two to five days. Light does not matter because we just want to know if the seeds will sprout.

After three to four days, check and see which seeds have germinated. Some seeds may take a couple more days to germinate, so check again at seven to nine days. The percentage of seed germination in the towel gives you a good idea of how the seed will do in your garden. (Seven germinated seeds = 70 percent germination rate).

It’s good to know the average days to germinate for each type of seed to see if it takes longer than the three to four days for most of my seeds. Check out this detailed factsheet from Penn State, complete with charts and germination days at: or find a seed packet for that type of seed/plant for more information.

When it comes to saving seeds, some last longer than others. Spinach, corn, and Swiss chard last only about one year or two, at normal household conditions. Beans, carrots, squash, tomatoes, squash and turnips can last up to five years. Flower seeds vary widely. So the way you collect and store the seed is very important.

Collected seeds should be cleaned and dried, then stored at about 50 degrees and in a dry location. I store seeds in the garage, it often gets lower than 50, so I tuck them under a tarp. Light should be kept at a minimum. If you have leftover seed packets, put them in a jar, seal the jar, store in garage, unheated porch or refrigerator.

When buying new seeds, check the packet for days to germinate, and percentage of germination. Let this be your guide when looking for those first sprouts to appear. I also use this as a guide to how many seeds to drop in a hole when planting. My rule of thumb, first I’m less likely to buy seeds with below 60 percent germination; I figure I’ll be lucky to get 40 percent. If the germination rate is 70 percent, that tells me to drop more seeds. If it’s 90 percent or better, less seeds.

For a complete guide on saving and storing seeds, visit

Marilyn McKinley is an OSU Extension master gardener volunteer in Mahoning County. Winter hours for the Plant and Pest Diagnostic Clinic vary. Submit questions to the clinic at 330-533-5538 or drop samples off to the OSU Extension Office in Canfield.

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