Seed Shelf Life Demystified: How Long Are Your Vegetable Seeds Good For?

We get asked this question all the time: “how long do vegetable seeds last?” The answer is simultaneously simple and complicated. However, we can break it down for you.

At Sow True Seed we get germination tests performed on every seed variety no less than twice per year. While, legally, we are only required to do germination tests once a year, we do it twice to ensure that we’re providing the highest quality seeds possible. Because we have all this data, we have a pretty good idea of how long seeds last, which we’re going to define as germinating at or above legal federal germination standards.

Fun Fact: The seed variety we’ve had the same stock of for the longest period of time is our lot of Rutgers VF Tomatoes, clocking in at 13 years!

How Long Do Vegetable Seeds Last? Essential Storage Tips For Gardeners

Understanding seed longevity is essential to having an efficient and productive garden. Seeds, even when not planted, are very alive little organisms! Inside that delicate seed coat is a plant using its energy sources to stay alive in order to eventually sprout when the conditions are right. Different species of seeds are going to have different levels of energy sources that will dictate how long they can last.

Do Seeds Expire? Understanding Seed Shelf Life

So, do seeds expire? Eventually, yes, they do. However, in most storage situations what you’re going to see is a gradual loss of germination over time, rather than just one day none of them grow. The shelf life of seeds typically depends on the species.

You can expect your seeds to, on average, hold onto their optimum germination rates for as long as is dictated in the above chart, so long as they’re stored in the optimum conditions. From there, you can expect a gradual decline in germination percentage.

If you’ve seen our seed packets before, you may have noticed a “Sell By” date or a “Packed for” year. These dates are a legal requirement because seeds are technically considered a food product! However, they have no bearing on how long our seeds actually last.

Seed Storage: Preserving Your Seeds' Viability

You can expect tomato seeds to last for four to five years on average. Alternatively, onion and chives seeds typically only last for one to two years. Notice the range? Here are some tips to extend that range as long as you possibly can.

Store your seeds in a cool place. Why? Cool temperatures are important because they keep a seed’s internal mechanisms moving slowly and prevent it from using up its energy reserves too quickly.
Ensure your seeds stay dry. The seed coat needs moisture in order to break open and begin the germination process. Keeping your seeds away from moisture can stop this process from starting prematurely and extend the viability of your seeds.
Keep your seeds in a dark place. Light and the subsequent heat can break down seeds over time.

Ensuring these conditions in your seed storage area can help to elongate the lifespan of your seeds for as long as possible.

Effective Seed Storage Techniques for Gardeners

When people ask us how to store seeds, our response is typically to keep your seeds in an airtight container in the refrigerator. This can be a good tupperware or a mason jar or any other number of containers. But, fridge room is sacred and we get this! Keeping your seeds in a storage cabinet, a temperature controlled garage, or closet can also do the trick. There are a wide range of seed storage methods, however you’re going to find that all of them include cool temperatures, limited light exposure, and dryness.

Seed Packet Lifespan: How Long Can You Keep Them?

Seeds, whether in packets or not, are going to be subject to the same variables when in storage. We still recommend keeping your packets in a cool, dry, dark place. Seed packets left out in your car, on the counter, or in the garden will still lose viability over time. We love to see an organized filing cabinet for seed packet storage! Or an airtight recipe box can also do the trick.

Avoiding Common Seed Storage Mistakes

We’ve all made the common seed storage mistake - we buy our seeds and they sit out on the counter. Or you’re drying seeds you’ve saved and leave them longer than you should - it’s okay! But preserving seed quality should be of the utmost importance to your gardening practice. Here are some don’ts for seed storage:

Don’t store your seeds in a non-airtight container. We can’t always control humidity in the fridge, the garage, the basement, or even the main floor of your house. Keeping your seeds in an airtight container can help ensure that the humidity can’t get to them.

Don’t let the mice get to your seeds! They love them (and for good reason) but losing your seed stock to these pests can be a financial blow. Keep your seeds in a mouse-free area in a container they can’t chew through - and perhaps even set some traps.

Don’t leave your seeds in a room, shed, or garage that is not temperature controlled. The constant freezing and thawing of seeds can lessen their viability.

Don’t open a cold seed storage container straight from the freezer. While it’s safe to store totally dry seeds in an airtight container in the freezer, you should always allow the container to come to room temperature before opening it, as the cold seeds will attract condensation as they warm up in the open.

Remember: Quality Seeds Need Proper Storage

Sow True Seed’s high-quality vegetable seeds are meant to last for a long time. From field to packet, they are treated with the utmost care. And quality gardening begins with quality seeds. But seed viability depends on you as well!

	*Article Written by: Hannah Gibbons*
	About the Author: Hannah Gibbons, an employee at Sow True Seed since 2020, has nearly a decade of experience in the agricultural industry. Their passion for environmental education and regenerative agriculture has been the cornerstone of their work, aimed at making gardening accessible to all.