How Long Does Grass Seed Last When in Storage? The Complete Answer

One of the most frequently planted but also most misunderstood plants is grass. Most people who care about their lawn will have a bag or two of grass seed in storage.

That leads to one of the biggest areas of confusion concerning grass seed – how long does grass seed last in storage before it is no longer usable?


The answer just might surprise you. Take a look at some facts and information regarding stored grass seed:

Is It Ok To Store Grass Seed?

Grass Seed

You might be wondering whether you should even think about storing grass seed in the first place. After all, it’s not that expensive, and it’s very easy to find in the lawn and garden shops in the spring.

The truth is it's perfectly OK to save any leftover grass seed that you have. Why spend more money on something you already possess?

If your leftover grass seed is not in its original bag, you may want to mark the date you put the grass seed in storage on. We will explain why in more detail later in the article.

What Is The Best Way to Store Grass Seed?

Pile of Grass Seed

Grass seed that has never been opened is best left in the original packaging it came with. If the bag has been opened, transfer it to another container. If it has not gotten wet, some people say you can store it in an airtight plastic tote.

Most lawn and garden experts will tell you the seed needs to breathe so store it in a cloth bag. The air circulating through the sack will also help the grass seed to stay dry.

It is very important that you store the bag of grass seed in a dry place. If the seed gets wet, there is a good chance that mold will form on it. If you find that your stored bag of grass seed has gotten moldy, then it's best just to toss it out.

Temperature is important as well. You want to store grass in a cool place, away from the sun. Grass seed tends to survive storage the best when it is kept at a temperature less than 50 degrees. You definitely do not want to store grass seed in an area that maintains the constant 70 degrees of temperature.

It’s even OK if the place you store your grass gets the freezing temperature. Seeds of grass will go dormant in a bag just like they will in the ground in your lawn. They will come back to life again no problem when the temperature warms up.

You don’t want to store grass seed on the floor either because it can easily get wet, and it’s accessible for rodents. It is actually a good idea to put out some packs of scent around your stored grass seed to help keep mice away.

Here is how the experts store grass seed:

How Long Can You Store Grass Seed For?

Handful of grass seeds

So now that you know it’s OK to store grass seed and how to store it, you are probably wondering how long it’s good for.

That is a very fair question. It is true that some grass seed, when stored, will lose its ability to germinate over time. All the experts agree on that. What they don’t agree on is the percentage of grass seed that goes bad in storage in a year’s time.

Manufacturers and scientists estimate that anywhere from 5% - 25% percent of stored grass seed is no longer usable after a year.

So according to those figures, grass seed needs to be thrown out anytime between 3 and ten years depending on what expert’s theoretical percentage of stored grass seed failure you feel is most accurate.

Test To See If It Will Still Germinate

Green grass and seed

There is a simple way to test to see if your stored grass seed will germinate. Put a teaspoon of grass seed in a paper towel and then wet the paper towel. Seal in in a Ziploc bag in a place that gets light but not direct sunlight. If a large percentage of the seeds sprout in a week, your seed is still good.

Here is a generic video on how to test any old seeds to see if they will grow:

Better to be Safe than Sorry

planting grass seed

We have given you lots of information here but have not given you a firm answer as to how long grass seed lasts in storage. Perhaps that is because it is hard to determine an exact right answer.

Based on what you have learned here we have a suggestion. Try not to keep your stored grass seed over two years.

There is a pretty good bet that during those two stored years a large percentage of the grass seed will still germinate. After that, you are just rolling the dice as to whether your grass seed is any good.

Since it’s better to be safe than sorry, don’t take a chance. Grass seed is not that expensive so go ahead and replace after two years, so you don’t waste your time putting down bad grass seed.

Let us know if you found this article helpful and we always welcome constructive comments.

About the Author Laura Bennett

Hello, I’m Laura Bennett. I love nature especially when it comes to flowers and different kinds of plants. I started a very small garden behind my house and I named it Humid Garden. So, I created this blog to provide aspiring and inspiring thoughts about gardening for gardeners and anyone who has the intention of keeping a garden.

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