After you’ve been gardening for a few years, one of things you have to start paying attention to is seed viability, or how long your seeds will last. Every year you buy packs of seeds and unless you’re a commercial gardener, you’ll rarely use all of them in a single season. It’s important to know that seeds have a shelf life and that amount of time varies for the types of seed.
How long your seeds will last is not always absolute. What you’ll find here are general guidelines, but the experience can vary significantly based on the genetics involved and how they are stored. Even if you use absolutely perfect seed storage and germination techniques, it’s entirely possible that some seeds won’t sprout. It’s just a part of nature.
Below we discuss some means of testing seed viability if you want to see whether your seeds are still good or not and this is usually the “best” way to determine if your seeds are viable. We also provide some helpful tips on how to store your seeds.
Following are some general guidelines that indicate how long popular seeds will last when well cared for. See a little bit further on for seed storage tips.
Vegetable Seed Viability
|Vegetable Seed:||Seed Viability:|
|Brussels Sprouts||4 years|
|Chard (Swiss)||4 years|
|Cress (Watercress)||5 years|
|Summer Squash||4 years|
|Winter Squash||4 years|
Herb Seed Viability
Flower Seed Viability
|Flower Seed:||Seed Viability:|
|Sweet peas||2-3 years|
|Sweet William||2 years|
Testing Seed Viability:
If you’re not sure whether your seeds are still good, there is a way to find out. You’ll want to do this well ahead of your planting schedule, since it can take some time for the seeds to germinate.
The easiest way to test seed viability is using the paper towel method. Take a single paper towel and fold it in half two to three times and then moisten the towel with tap water. In between the flaps of the paper towel, sprinkle five to ten seeds. Close the paper towel flap and place the folded paper towel inside of a Ziplock plastic bag, zipping the bag up to retain moisture. You can place the bag virtually anywhere, it doesn’t need direct light or artificial lighting to germinate.
Wait for the initial germination time to expire and check the seeds to see if you see any sprouts. If you do, great, your seeds are still viable! If not, fold the paper towel back up, insert into the bag and zip it back up again. Check your seeds every couple days for a sprout. If you haven’t seen a sprout by the maximum germination time, chances are good your seeds are no longer viable and should not be planted. Time to buy more seeds!
How To Store Your Garden Seeds:
It’s a good idea when you buy seeds to clearly mark the year that you purchased the seeds on the packet. Some packets are marked with a “sell by” date, and this is usually the year you buy them, but if not make sure you can figure out how old your seeds are easily.
There are many techniques available for storing your seeds from season to season. Dry and cool is the golden rule. Generally speaking, you want to keep the seeds in their original packets, or an envelope if you don’t have a packet. These packets and envelopes should be placed inside another container, preferably as airtight as possible. Keep the seeds in a cool place, but not freezing, and they should last for the expected amount of time.
If you want, you can store seeds in your refrigerator if you have the space. If you do this, make sure your storage container is airtight (with a seal) so when you take the seeds out, you’re not subjecting the seeds to moisture as they warm up. Try to avoid storing the seeds where the refrigerator vents from the freezer, and also never store seeds in your freezer!
If you’re collecting your own seed from your garden, it will be important to make sure you’ve removed all moisture from the seeds prior to storage. You can place the seeds on a paper towel and allow them to air dry for some time prior to storage. Once dry, simply place them into an envelope and then your storage container.