Garden DIY · Vegetable Gardening

Can You Plant Old Seeds?

It is so easy to get carried away when ordering seeds – believe me, I know. I have seeds saved in a Seed Keeper bin, a shopping bag, and a cabinet in my office. Save yourself from extreme seed shopping. Before you even consider placing an order for seeds this year, take an inventory of the seeds left from previous years.

Many seeds remain viable for several years; others are only usable for one season. There is little more disappointing to a gardener than to plant seeds and wait for seedlings that never sprout. There is some debate about seed viability, but this is a general guideline.

The first step is to check seed packets for the sell by date. If seeds are close to the end of their shelf life, some gardeners just hedge their bets by planting more seeds than is recommended. If the date has long passed or you would prefer a more scientific method, there are a couple simple tests to check the viability of seeds.

For the first test you need paper towels, water and seeds. Begin by dampening strips of a paper towel.

Place ten seeds of each type of seed being tested in a row at one end of the paper towel.

Fold the seeds up in the paper towel and put them in a sealed zip lock plastic bag to keep the paper towel moist. Remember to label each plastic bag if you are testing more than one type of seed.

Put them in a warm location out of direct sunlight, and check them every day to be sure the paper towel stays moist. Mist it if it starts to dry.

Determine the germination rate of your seeds. It can vary significantly depending on the type of plant. The rate of germination is often found on the back of the seed packet or online sources are available.

When the expected time of germination has passed, open the paper towel and see how many seeds have sprouted. In my test, 8 of 10 radish seeds germinated; all the pea seeds sprouted; and 8 of the kohlrabi seeds were in various stages of germination. All three varieties were eager to grow!

The only supplies required for the second test is a cup of water and the seeds.

Simply place ten seeds of each type of seed being tested in the cup of water and wait at least fifteen minutes. Seeds that sink are viable; floaters are probably not.

The results of this test are sometimes challenged for reliability. In my test, 9 of 10 radish seeds sank; all of the pea seeds were at the bottom of the cup; and just 1 kohlrabi seed floated. The results of this test were consistent with the first one.

Each gardener can set her own guidelines to decide when the seeds should be kept or discarded. If six or more of the seeds sprout, I keep them. If the number of sprouts is five or less, I throw them away. Of course, these guidelines can vary with the type of seeds. Some plants are notorious for lower germination rates.

Shop your own stash of seeds before placing new orders this year. You will save some money and give leftover seeds a chance to do what they were meant to do – grow! Garden with me!








2 thoughts on “Can You Plant Old Seeds?

  1. I’ve always use the paper towel test for testing viability. Never tried the cup and water method. Very interesting!

    The great part about using the paper towel method is, if you have limited seeds you can carefully remove the sprouted seeds from the paper towel and plant them as you would in cell packs. This also gets the seeds started sooner, which is nice for seeds that take longer to germinate.

    Look forward to following your blog!

    Julia Dimakos

    1. Normally, I don’t do the paper towel test until I am ready to plant seeds for the reason you said. I plant the sprouted seeds so they can grow to their potential. It is way too soon for me to start seeds but I wanted everyone to know they could do this before they ordered seeds they didn’t need. Timing, as they say, is everything!

      Thanks so much for taking the time to comment. I really appreciate it!


      P.S. I really liked your post on growing microgreens!

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