It’s MARCH 1st, the unofficial start to spring … well in my book anyway! Spring is my most favorite season & March is one of my favorite months ~ bring on all things gardening, am I right! But before we get growing, we should probably check to see if those seeds collected after last years growing season will germinate. Here are some tips I hope you find helpful + a handy little chart on the shelf life of certain flower seeds.
If you’ve started planning your spring garden like I have because I can’t wait, you might be taking stock and seeing what materials you have to work with. Are you wondering if the seeds you intended to use from last year are still good? What about those heirloom seeds you collected a few years back? Well, like most things in nature, seeds have a shelf life so you need to determine your seeds’ ability to germinate before you start planting. You don’t want to waste your time and effort!

Most brand new seeds have a 90% germination rate, meaning that every 9 out of 10 seeds you plant should grow. However, if you’ve got seeds that have been hanging around for three years, the germination rate drops to around 60%. That means you’ll need to plant a higher number of these older seeds to increase your chances of growing something.
Seed Viability Test For Older Seeds
If you have older seeds, it’s wise to do a quick viability test prior to planting when using older seeds. Here’s what to do:
- Fold a dampened paper towel in half.
- Take 2-3 seeds and place them on the damp towel.
- Fold the towel over the seeds and place them in a zippered plastic bag or airtight container in a warm location.
- After a few days, open the bag and take a peek to see if any sprouted. This will give you a good gauge of how your seeds are germinating.
If the germination rate is low, but there is still some viability (for example, maybe only 2 of the seeds in your test sprouted), simply plant more of those seeds in the garden, knowing that not all may sprout. You’re just increasing the sprouting odds.
The key to keeping your seeds viable for a few seasons is proper storage. Be sure to do the following:
- Keep your seeds in a cool spot that offers a consistent temperature. Your best bet is to put them in a moisture-proof sealed container (if they’re already in packets, you can keep them right in the packets while storing) and store in your freezer or refrigerator. It is extremely important the seeds are 100% dry or mold will develop. You can even add some rice to the container to wick away any possibly moisture.
- Keep them out of direct sunlight.
- Keep them away from any humidity or moisture.
How you store them won’t only be for the long-term, it will be your day-to-day access while you’re outside sowing.
Storage Life Of Flower Seeds
Flower | Storage Life |
Ageratum | 4 years |
Alyssum | 4 years |
Amaranth | 3 years |
Aster | 1 year |
Baby’s Breath | 2 years |
Bachelor’s Button | 3 years |
Calendula | 5 years |
Celosia | 4 years |
Clarkia | 2 years |
Coleus | 2 years |
Columbine | 2 years |
Cosmos | 3 years |
Dahlia | 2 years |
Daisy | 3 years |
Delphinium | 1 year |
Dianthus | 4 years |
Foxglove | 2 years |
Geranium | 1 year |
Hibiscus | 3 years |
Hollyhock | 3 years |
Impatiens | 2 years |
Larkspur | 1 year |
Lobelia | 3 years |
Lupine | 2 years |
Marigold | 2 years |
Nasturtium | 5 years |
Nicotiana | 3 years |
Pansy | 2 years |
Petunia | 3 years |
Phlox | 1 year |
Poppy | 4 years |
Salvia | 1 year |
Snapdragon | 3 years |
Sweet Pea | 3 years |
Verbena | 1 year |
Zinnia | 5 years |
**Farmers Almanac credit