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Does Grass Seed Go Bad? 5 Things You Should Know About Grass Seeds

Grass Seeds

You notice a bare patch in your lawn, and you immediately think of the grass seed bag lying in your garden shed. You feel happy and get to work; plant the seeds, and then add fertilizer. However, even after watering it regularly, you notice that the bare patch remains bare! This has happened to me.

I used some old grass seed to plant on my lawn. I waited for a few weeks and replanted but the same result. Nothing happened. I noticed some scruffy growth here and there, and that’s it.

I asked a friend who is an expert in lawn maintenance. He wanted to know how old the seeds were. I was surprised and asked, “Does grass seed go bad?”

He told me that the germination rate of grass seed decreases as it ages, resulting in a bad, spotty, or no growth at all.

Does Grass Seed Go Bad

Does Grass Seed Go Bad?

The clear answer to this question is yes, but this happens after a considerable period. Most gardeners don’t think of this factor when stocking up on grass seed. They like to be well prepared and keep bags of grass seed in storage.

Does Grass Seed Go Bad Canada Green Grass Lawn Seed
Canada Green Grass Lawn Seed via

Usually, grass seed is good for the first 18 months or so. After that, you will notice a steady decline in its quality. Generally, experts have estimated that the grass seeds will lose their germination rate by approximately 10 % every year.

You must also keep in mind that even the new seeds are not 100 % effective. On the packs, they only promise a 90 % germination rate. Starting with 90 %, it will be down to 80 % the next year and another 10 % down the year next to that. This decline mainly depends on two things:

  • Variety of plant/grass
  • How the seeds are stored

Other Factors Affecting the Effects of Grass Seed

As we mentioned earlier, the germination rate of grass seed goes down steadily with time. It mainly depends on factors like the variety of grass plants and storage conditions. Apart from this, some other factors affect grass seed quality. These are:

  • The moisture content of the seed. All seeds have internal moisture, and a level between 10 and 20 % is ideal. Seeds that lose moisture and fall below this level or absorb too much moisture are more likely to die.
  • Storage temperature is also essential. It is best to store them above freezing temperature but under 60 degrees Fahrenheit.
  • Humidity levels have to be just right because too much humidity can cause rot, while too dry seeds can only lose all nutrition and wither away.
  • Pests are another big problem for grass seed. Pests can attack seeds and leave only the chaff. Insects are one of the most common enemies of stored seeds.

Why Should You Store Grass Seed Properly?

Obviously, it would be best if you tried to store grass seed properly  otherwise, it may get spoilt. The grass seeds are quite expensive, depending on the variety, and you don’t want to lose your hard-earned money in this way.

Moreover, when you really need the seeds to fill in the scanty or bald patches, you will be disappointed with bad seeds. It would be best if you remembered that even new seeds don’t have a 100 % germination rate.

How To Store Grass Seeds Properly

For any gardener, it is essential to know how best to store grass seeds. It will save both money and time. Here are a few things that you can try.

  • Store In A Cool Place: extreme heat can damage the seeds or inhibit their growth and prevent them from germinating.
    • Keeping the seeds in a garden shed is not a good idea if the weather is hot. Generally, seeds are better in colder environments.
    • If you plan to keep them frozen, then continue to do so for the whole storage period.
    • Fluctuations in temperature are not good. One good option is to store the seeds in your basement or inside the garage in a shady, cool place.
  • Keep Away The Pests: clean the storage space and apply pesticides before storing any seeds.
    • If you notice any rodent holes or hideouts, then seal them tightly.
    • Pests can ultimately damage the seeds, so ensure that the area is well protected. Check regularly for any kind of pest infestations.
  • Labeling: be systematic and well organized with the seeds.
    • Suppose you are going to change the original bag even more so.
    • Clearly label the details like the name of the seed, expiration date, and when you stored it.
    • It will help you in keeping track of the older seeds.
  • Airtight Container: pour the leftover seeds into a plastic container.
    • If the original seed bag is still there, then you can leave the seeds in it and put the whole thing in a container.
    • Make sure that this is rodent proof and airtight.
    • To keep the moisture level down, you can place a small pouch of baking soda in the seed bag.
  • Unopened: if the bags have not been opened, you can place the bag in a cool and dry place like your basement or garage. Just make sure that the seal is tight.

Conclusion – How Long Can You Store Grass Seeds?

It is essential to give the grass seeds the best chance to start, as improperly stored, or old seeds can become less effective.

Most grass seeds have an expiry date of about 2 years, and some can even last for 5 years. If you keep storing old seeds beyond the expiry date, then you are basically keeping useless seeds.

Storing for more than 18 months can leave the seeds’ germination rate at a very low level. There are a few things that you can try to bring old seeds back to life.

  • Apply starter fertilizer liberally
  • Water up to 2 or 3 times, especially in hot weather.
  • To make up for the low germination rate, you may have to overseed.
  • Always buy high-quality seeds and store them properly to get the best results.