If you want your lawn to look the best it can but it’s spotted with a few bare patches, you might be considering planting some more grass seed. Grass seed can fill in these gaps and leave with you with the lush and green lawn of your dreams.
However, if it’s been some time since you last planted any grass seed, you may have an old bag of seed lying around. This may lead to questions of whether the grass seed is still good or whether it has expired.
In this article, we’ll look at all you need to know about grass seed and whether it can expire. We’ll explain how to store grass seed, how to check if grass seed is still good, and when is the best time to plant it.
Let’s get started!
Does Grass Seed Expire?
We’ll begin by answering the question of whether grass seed can actually expire or not.
The answer to this question is that yes, it does. However, this is a very gradual process. You will find that the older your grass seed is, the less it will germinate and the less grass you will get.
As a general rule, we would advise that you only keep grass seed for around two to three years from the date of purchase.
Try to use it within that time frame as after three years have passed, the germination rates will be too low for them to really be worthwhile planting.
On average, the germination rate of your grass seed will decrease by around 10 to 20 percent for every year that passes once the seeds have been stored for two years.
This means that grass seeds that are less than two years old can germinate at a 100 percent success rate but grass seeds that are 10 years old will only have a rate of around 20 percent.
How Long Does Grass Seed Keep For?
You may think that as grass seed is good for two years without beginning to degrade, that would mean that grass seeds can keep for two years.
However, that is not always the case. There are some factors that can affect how long Grass seed will keep for and we will look at these now.
In general, an unopened bag of seeds will keep for longer than a bag that has been opened. As a general rule, an opened bag of seed that has been correctly stored can last for up to 18 months without any reduction in the rate of germination. On the other hand, a bag that hasn’t been opened can last for around five years.
This does depend, however, on the type of grass seed. Seeds that are suitable for harsher conditions and thrive in hardiness zones three to nine can last up to 5 years.
This includes common grass seed varieties such as Ryegrass. Other varieties such as Fescue and Bermuda may only last up to three years.
You should always keep in mind that the longer the grass seed is stored for, the more the germination rate will reduce. Even when properly stored they will still be a degradation in the quality of the seeds
Do Grass Seeds Go Bad When They’re Expired?
It’s not easy to tell if your grass seeds have gone bad. There are no visible signs of reduction in germination so other than checking your dates, you will not know if your seeds have gone bad.
Even the expiry dates on the bags are only rough estimates as other factors will affect how quickly the seeds will degrade.
If you’re concerned about your seeds, you may be able to see a few signs that they are no longer any good. These aren’t always easy to spot, however, so you will need to look closely.
One of the more obvious signs is the visible signs of fungi. If you do see anything like this you should dispose of the seeds immediately.
Some harder-to-tell signs include seeds that feel damp and clump together. If your seeds are like this you should also throw them away immediately.
How Should You Store Grass Seed?
We mentioned in the previous section that storing the grass seeds correctly it’s very important. If they’re not stored correctly then they will degrade and expire more quickly.
So that asks the question of how you should store grass seed.
Where Should I Store Grass Seed?
Many people suggest storing grass seeds outside. They may have a space in the shed or garage to store the seeds.
This is often very convenient as it keeps the seeds out of the way and will also keep them nice and dry and out of any bad weather. However, these are not always the best place for grass seeds.
Sheds and garages can keep seeds away from water and snow, but won’t protect the seeds from heat and humidity.
High temperatures and humid conditions are not ideal for grass seed and I will make the seeds degrade more quickly.
A better place to store grass seed is in a cool location that can also remain dry. If you have a cellar or basement these are ideal. You want to keep your grass seed kept at temperatures between 40 to 55 degrees Fahrenheit.
If the temperatures are frequently higher or lower than these ranges your grass seed will not stay as fresh for as long.
If you don’t have a cellar or basement, Store your grass seed in a place that is away from direct sunlight, dark, cool, and free of humidity. An air-conditioned room is ideal.
What Type Of Bag Should I Use?
Even a bag of seeds that haven’t been opened yet should have adequate airflow. It’s important that air can get around the seeds.
We would recommend storing your grass seeds in a breathable bag. It should have a convenient way for air to circulate such as mesh air vents.
Burlap sacks are also a great option. These types of bags will allow air to circulate inside and also prevent any bugs and insects from getting into your seeds.
You can also add a small container that has some baking soda inside. If you play this inside your bag of grass seeds, it will absorb any moisture and prevent the grass seeds from growing any fungi.
If you’re storing several different types of seeds, you should keep them separate from each other. This will also prevent the buildup of moisture in your seeds.
Can You Freeze Grass Seed?
You might be wondering if it is safe to freeze grass seeds. In many cases, freezing things can prolong the life span so it’s only natural to wonder if grass seeds are the same.
Although you can freeze grass seeds without damaging them or causing any loss in germination, they should only be frozen for a short period of time.
Grass seeds are often exposed to short-term freezing during their lifespan so there’s no reason why you can’t freeze your grass seeds too. However, it won’t really extend the lifespan by much so there isn’t much benefit to be had from freezing them.
You should be extra careful with warm season seeds, however. Many of these aren’t built to survive cold temperatures at all so freezing them does run the risk of damaging them.
We would only really recommend freezing seeds that are cold season seeds and are more resilient to cold temperatures.
How Do You Check If Grass Seed Is Still Good?
Checking to see if your grass seed is still good to be planted is an important but easy process. You will no doubt want your garden to look its best but planting grass seeds that won’t properly germinate won’t give you the dream lawn that you want.
It’s always best to check that your seeds Will give you the lush results that you want before you plant them.
Here are three easy steps to check if your grass seed is still good.
Step One
Take a sheet of paper towel or kitchen towel and moisten it a little with some water.
Step Two
Take around half a dozen grass seeds and place them on the paper towel. You should then put the paper towel and seeds in a warm location, for example near a radiator or on top of your clothes dryer. Leave the towel for two to three days.
Step Three
After the two to three days have elapsed, check your seeds. If any of them have begun to sprout, then they are still good to be planted.
If they haven’t sprouted, or only one or two of them have, you should throw away the bag of grass seeds and buy some new ones.
When Is The Best Time To Plant Grass Seeds?
It’s important to know when the best time to plant grass seeds is as this can affect how you store them. If you buy some grass seeds and have plans to plant them within a couple of months then you don’t need to worry too much about how they are stored.
However, if you’re not going to plant them for the best part of the year, you may want to follow some of the tips in this article so you can keep them as fresh as possible.
If you want your grass seeds to germinate as quickly as possible, then the best time to plant your seeds is between late summer and early fall.
These months give you the best conditions as your soil will still be warm, the evenings will be cool, and the temperatures should be more moderate than they would be during the height of summer.
If for any reason you miss this window of opportunity, you should instead aim to plant your seeds in mid spring.
When planting grass seeds in mid spring, you should make sure that you water the seeds as often as you can. This will help them germinate better and more quickly.
Final Thoughts
In this article, we took an in-depth look at whether grass seeds expire or not. We found that grass seeds are at their best when they are up to two years old and that the older they get the lower the rate of germination will be. Grass seeds that are ten years old may only germinate at a rate of one in five.
You can try to prolong the lifespan of your grass seeds by storing them correctly. Keep them in a room that is cool, dry and free of direct sunlight and make sure they’re in a bag where air can circulate freely.
We hope that the information, hints and tips in this article will help you plant your grass seeds and have a beautiful lawn.