Does Grass Seed Go Bad? [Prevent Your Seed Expiring]

does grass seed go bad

Spreading grass seed is a great way to expand or thicken up the lawn. It’s affordable, easy to use, and has a rather high success rate. The question is, does grass seed go bad?

So, does grass seed expire? Yep, grass seed goes bad in approximately three years, even if it is stored properly. Some types may last a bit longer (up to five years), others may go bad as quickly as two years. The best way to prevent grass seed from going bad early is to keep it dry and store it somewhere with no moisture. Another option is simply using it all before its expiration date arrives.

Below, we have a closer look at grass seed, why it goes bad, how to tell if it’s bad, how to store it properly, as well as some frequently asked questions.

How Long Is Grass Seed Good?

On average, grass seeds are good for between 2 and 3 years. That said, if stored improperly, grass seed may start going bad within weeks or months rather than years.

The following factors may impact how long your grass seed is good for:

  • Where it is stored (a dry location is best)
  • How it is stored (air-constricting containers are best)
  • Quality of the seed and type of the seed
  • The expiration date of the seed

Why Does Grass Seed Go Bad?

Most of the time, old grass seeds goes bad due to poor handling or improper storage. The good thing is that it’s easy to avoid causing your grass seed to go bad.

Grass seed is quite delicate compared to many types of seed and goes bad quickly if exposed to high levels of humidity and moisture or excessive sunlight. Rodents are also a real issue with grass seed, as they may get into it and contaminate the whole batch.

Molding, fungi growth, and early sprouting are among the most common side-effects of improperly stored grass seed.

will grass seed germinate on top of soil

How To Tell If Grass Seed Is Bad?

Grass seed that’s bad, for the most part, is fairly easy to spot as fungi begin appearing on it as it turns. However, sometimes it’s trickier to notice that your grass seed has gone bad.

The following simple steps help you identify bad grass seed:

  1. Separate out some grass seed and place it on a moist paper towel
  2. Fold the paper towel in half, with the seeds inside, and seal it up in a ziplock bag
  3. Stick the bag somewhere warm but out of the sunlight
  4. Check the bag daily and add moisture as needed

If no growth is observed after 7 to 14 days, you’re dealing with grass seed that is no good.

How To Prevent Grass Seed From Expiring?

To preserve your grass seed and use it again next year you’ll need to preserve it if you want optimal results. Improperly stored grass seed is prone to mold and rot, which may not be usable.

Here’s how to prevent your grass seed from going bad before its time has expired:

  1. Proper storage in airtight containers
  2. Place containers with seeds somewhere dry
  3. Make sure the seed is completely dry before storing it

Depending on the grass seed you’re using, the original packing may have come with storage instructions. If so, take care to follow the instructions as closely as possible.

DON’T MISS: How long does grass seed take to germinate?!

Are Expired Seeds Usable?

The little bits of fungi that pop up on expired or “bad” grass seed seem like a pretty big indicator that it isn’t fit for use. That, however, isn’t really the case at all because you can still use expired grass seed with some results.

Even more, some folks claim to have achieved results equal to results from fresh seed, when using expired grass seed (even with a bit of visible fungus on it).

How To Store Grass Seed

Here’s my top tips to store grass seed properly:

  1. Allow grass seed to dry out fully
  2. Place grass seed in airtight bags or containers
  3. Place the bags or containers in a metal tub or plastic tote with a lid
  4. Stick the tub or tote somewhere dry and cool (not your garage or shed, where it gets hot)

The key is, don’t let your grass seed expire! If you’re looking for a little bit more information, he’s a great video from Ryan Knorr lawn care on storing grass seed.


Frequently Asked Questions:

How Do You Know When Grass Seed Goes Bad?

When grass seed goes bad it has an aroma like old wet grass and lumps up. Bad grass seed may also change color due to fungi or mold growth. Proper storage of grass seed is the best way to avoid it going bad earlier than it should.

How Should I Store My Grass Seed?

The number one factor to successfully store grass seeds is keeping it completely void of moisture. That means you need to store it in a plastic bag with a zip-top or a container with a sealing lid. Keep the bag or container of grass seed in a tote or tub with a lid if possible, to keep rodents out. Store the grass seed in a basement or somewhere else cool and dry.

Can I Use Old Grass Seed?

Old grass seed might not look pretty, and it may not work as well as fresh grass seed, but there’s no reason you can’t use it if you have a mind to. That said, don’t expect to see as much new growth as you would from healthy grass seed.

Is the Garage O.K. for Storing Grass Seed?

Technically speaking, yes, grass seed can be stored in the garage. However, it is not the greatest choice of places to keep your extra grass seed. Garages tend to have fluctuating temperatures and may be too hot for properly storing grass seed for part of the year. Basements are more reasonable locations for storing grass seed as they are drier and cooler all year.

A Final Word About Grass Seed Going Bad

Grass seed expires after approximately two to three years. That’s why you should plan on using it within 24 to 36 months of purchasing it.

Hopefully, the information presented above will help you properly store your grass seed and avoid it going bad early.

The most important things to remember about keeping grass seed from going bad are that it needs to be kept dry, cool, and out of the reach of rodents.

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