How Long Does Grass Seed Last All You Want To Know

How long does grass seed last? Grass seed can last 18 months–5 years after the label test date. Grass seeds only last a certain amount of time, whether you just seeded your lawn or keep an extra bag on hand for bare patch repairs.

These seeds interact with the air and moisture in the environment because they are living organisms, which can alter their chances of germinating. The lifespan of grass seeds depends on how they are stored, though unopened bags may last longer than opened ones.

Continue reading the post to see more detailed information that I will present to you.

What Is Grass Seed?

The term “grass seed” refers to a variety of grass species that are used as seeds for lawns, golf courses, and other ground coverings.

Although there are numerous varieties of grass, there are primarily two types: cool-season grasses and warm-season grasses.

Warm Season Grass Seed will thrive in warmer temperatures, while Excellent Season Grass Seed typically grows best in cooler climates.

These include Bermuda grass, Fescue, Rye grass, and Bluegrass as some examples.

The type you should use will depend on your location and how much sun your yard receives daily, as some varieties require more light than others to thrive.

Factors That Affect The Grass Longevity 

The longevity of grasses is impacted by numerous factors.

The climate and moisture level are the two most significant factors.

Your seed will probably last longer if you live in a humid area compared to a dry area (like Colorado).

How long your lawn lasts will also depend on whether there is enough rain to water it regularly.

If you want to make sure your seeds last as long as possible, here’s what we recommend:

The best place for them to be kept out of the way of heat, light, and excessive moisture is where you keep them.

That means choosing an airtight container, like Tupperware, to prevent them from slowly absorbing airborne pollutants while still allowing them to breathe. Transparent or opaque plastic containers work just fine.

You should keep them in a dark, cool environment for best results.

Your basement or garage are both great choices.

Moisture is a crucial element that affects the longevity of grass seed.

The humidity levels in your own home must also be taken into consideration when storing seeds to ensure that they aren’t subjected to more heat or light than necessary.

Here’s what we advise: lay a layer of lawn seed on top of a few paper towel sheets that have been placed at the bottom of your container.

This will eliminate extra interior moisture while still allowing air to pass through.

It would be best to keep them out of the way of windows so that no outside water seeps in over time.

By taking these steps, you can be sure that your new grass will continue to grow strongly for many years after it is planted. See more about How Long Does New Grass Take To Grow?

Types Of Grasses Available For Purchase

Grass seeds come in a wide variety and can be purchased.

The most prevalent variety, Kentucky bluegrass, thrives in a variety of soil types and climatic conditions.

Other common types include Rough Fescue (coarse-leaved), Tall Fescue (fine-leaved), Creeping Bentgrass, Bermuda Grass, Buffalo Grass, Perennial Rye Grass, and Creeping Bentgrass.

Each one has its pros/cons as follows:

  • Due to clay’s ability to conduct water, growing plants on clay soils with poor drainage or high pH levels may result in issues like chlorosis from iron deficiency.
  • Bermuda grass is a well-liked option for use in lawns because of its resistance to drought and positive traits like high salt tolerance and low maintenance needs.
  • Despite requiring more irrigation than buffalo or zoysia, tall fescue does well in hot climates.

While zoysiagrass requires warm temperatures all year long, buffalo will grow well when the temperature drops during the fall and winter.

What you’re looking for will determine the best type of seed; do you want something that grows quickly?

Does the area need to be resilient to extremely cold or hot weather?

Do you have grazing animals that could hinder the development of plants? There isn’t one “best” kind of seed, so make sure to research the options and find one that best suits your needs.

How Long Does Grass Seed Last All You Want To Know
How Long Does Grass Seed Last? All You Want To Know

How Long Is Grass Seed Good For Before It Starts To Spoil?

To increase your chances of having a green lawn, it is best to choose fresh, high-quality seed varieties. The longer they remain, the less viable they become, necessitating more seeding to fill in those bald spots, which may result in a weaker lawn.

But, with the right storage, grass seed lifespans range from 18 months to over five years, depending on the species you select and whether or not the pack is open.

  • Grass seed can last up to five years if it is kept properly sealed and unopened.
  • Open grass seed can last up to 18 months when stored properly.

On a box of grass seed you buy at the store, there will typically be a germination test date and germination rate. When new, germination rates are typically over 80%, so if you store your grass properly and use it within 18 months of purchase, this should be fairly accurate.

How Can I Tell If My Grass Seed Is Bad?

Can grass seed become stale? Yes, to answer briefly. Toss the seed if you see any signs of excessive moisture, mildew, or fungi. Test the grass seed first, though, if you’re unsure, before throwing it away.

Here’s how to tell if your grass seed is bad:

  1. Lay a damp paper towel on a spotless countertop.
  2. On the paper towel, scatter 10 grass seeds evenly along a row.
  3. Paper towels can be rolled or folded.
  4. In a ziplock bag, place the wet, rolled paper towel.
  5. For 7–10 days, place the bag in a warm location.
  6. Taking the towel out of the bag, count the seeds that have sprouted.

For instance, if nine seeds sprout, your success rate is 90%. You have a 50% success rate if only five seeds germinate.

You can compensate by scattering more seed, even if the germination rate is 50% or lower. Keep older grass seed on hand for overseeding tasks where it won’t be a catastrophe if some seeds don’t germinate. Get assistance overseeding your lawn from a local landscaping business.

Ways To Store Grass Seed To Make It Last Longer

How long grass seed lasts before going bad can be impacted by humidity, pests, storage weevils, sunlight, and drastic temperature changes.

Follow these tips to increase the lifespan of your grass seed:

The grass seed should be kept in an airtight, rigid, closed-top container.

  • Put the time you bought it or opened it on the label.
  • Before sealing the container, place desiccant packs inside to prevent humidity.
  • Keep the seed in a consistently dark, dry, and cool location.
  • For grass seed, temperatures between 40 and 50 degrees Fahrenheit are ideal.
  • Avoid using unheated garages or sheds.
  • Do not let the box touch the ground.
  • Make sure the storage container has plenty of airflow around it.

Select A Longer-lasting Grass Species

How long your grass seed lasts depends on the grass you choose for your yard. Perennial ryegrass, tall fescue, and Kentucky bluegrass seeds all have a 50% chance of germinating after three to five years in storage, according to research from Oregon State University. Even five years later, these rates still apply to creeping bentgrass.

Orchardgrass seeds, in contrast, might not provide these germination rates for one to two years after storage.

Choose Superior Grass Seeds For A Longer Lifespan

Crop quality and the life spans of grass seeds can be impacted by environmental factors and production methods. Choose superior seed from a reputable supplier that is kept in boxes rather than bags.

It’s not a good idea to purchase an unlabeled bag off the clearance rack. Finding a producer who seals their seeds immediately after harvest and before transport is a bonus.

Contact a local lawn care business if you need assistance choosing the best grass seeds for your lawn.

Amount Of Grass Seed Needed Per Square Foot

Depending on how many square feet of ground your new lawn will cover, you’ll need to buy a lot of grass seed.

Depending on the type and quality of grass seed you use, you may need as little as 15 pounds per 100 square feet or as much as 30 pounds. However, for common varieties, this number can vary.

Typically, more expensive grass seed varieties will require less seed than cheaper grass seed varieties.

In order to cover 100 square feet with a new lawn, for instance, you would only require about 20 pounds of a high-quality turf mixture.

Ask the seed vendor how many square feet the bag can cover when making your purchase and refer to the chart below before you buy.

For walking and playing space, a good rule of thumb is that you need 50 square feet of lawn per person.


It’s not as easy as stamping an expiration date on a seed bag. You can still get results from a bag of grass seed for many years, but the actual “expiry date” depends on how well you store your seed. While it is impossible to give a precise estimate of how much less viable a seed mixture can become over time, seed kept in a typical residential garage may experience a 10% annual germination loss.

The long-term viability of stored seed is significantly influenced by storage conditions. Due to the exposure to heat and humidity, storing your seed outside in a shed or garage is not recommended. To extend the shelf life of your seed purchase, try keeping it indoors in a cool, dry space.

I appreciate you reading.