How To Keep Cannabis Seeds Fresh Indefinitely?

Cannabis is a plant that has been around for centuries and has many uses. It can be used as a recreational outlet, but it also has medicinal properties. In recent years, the legalization of cannabis has made it more accessible to people who want to grow their own plants. If you are thinking about growing cannabis, you will need to know how to preserve your seeds for when you want to begin planting. In this blog post, we will discuss how to keep cannabis seeds fresh! 

The Foundations of Seed Storage

What is the best way to keep seeds fresh? The very act of seed storage means you are likely planning to hold onto your seeds for a while. Cannabis seeds can remain viable years after they have been harvested, but like anything else, there’s no guarantee that they’ll germinate (grow into baby plants) when they’re older.

There is no magic formula for seed storage; it’s ultimately up to you to decide how long your seeds will be able to remain viable in storage, and the only way to know that for sure is by testing them every few months (at least) after they’re first put into storage.

What you should aim to do is to create an environment that is cool, dark and dry. This will help to minimize the chance of your seeds sprouting before you are ready for them to, but remember that even if this does happen it’s not the end of the world.

Here are factors to consider:


The best temperature for storing cannabis seeds is around 60° Fahrenheit (15° Celsius). This applies whether you’re using a dedicated seed storage unit, or just keeping your seeds in their original packets.

Temperature fluctuations are generally bad for cannabis seeds; they should be kept consistently cool and dry. If this isn’t possible, try to make sure that cold spells aren’t too severe (especially if you’ll be storing the seeds for a period of time), and that humid spells aren’t humid enough to cause seeds to sprout.


Another big seed storage issue is light, so it’s best not to store your seeds near any kind of heat source, on top of cupboards etc., as this will likely expose them to light for at least part of the day. Again, this doesn’t mean that your seeds will definitely sprout if exposed to light – just that the chances of them doing so are slightly higher.


Bulk cannabis seeds can absorb moisture from the air, causing them to germinate or go bad more quickly. The best way to minimize this problem is by keeping your seeds in airtight containers.

Vacuum sealed glass jars are perfect for this, and will generally allow you to store your seeds for at least a year or so before they start to lose their viability and sprout. If you want to be more thorough than this, placing the jar inside a freezer bag (with as little air as is possible in the bag) will help extend the life of your seeds by preventing moisture from getting into them.

Airtight containers are another great way to store seeds, but you can’t use these for very long-term storage, since they aren’t completely airtight. Even so, it’s worth using these types of containers to store bulk seeds in – they’re likely to stay fresh for at least a couple of years.

What About Humidity? 

Cannabis seeds are very tough, and many growers say that their cannabis seeds have been unharmed by being stored in normal room humidity levels for several months or even years.

However, if you want the absolute best chance of your seed staying viable when you store it, it’s probably best to go with the rule of thumb that says your storage area should be in the same humidity range as a dry room (20-30%).

This will help reduce the chance of your seeds sprouting, and also make sure they don’t start to accumulate moisture. If you want to be really safe about it, you can place your seeds in the fridge (where they will be kept at 7-15° Celsius/45-59° Fahrenheit) for long term storage.

Methods of Seed Preservation

Contrary to how most people believe regular cannabis seeds last no more than 3 years, it is in fact possible for seeds to remain fresh indefinitely. Other types of seeds (such as feminized and autoflowering seeds) can be stored for much longer periods. Scientists aren’t sure why they de-germinate (become unviable) after this time but the leading factor may be due to environmental factors like heat and light which breaks down their ability to sprout.

It is possible to keep cannabis seeds for many years with no problems, but there are different opinions about how long this takes for different types of seed. Most people say that regular weed seeds have a maximum storage life of 2-3 years, but other people say differently.

There are many ways to extend the life of cannabis seeds, including cold storage, specialized containers and even experimenting with chemicals, but it is possible to store them using simple household items.

This method works well when you have a batch of old seeds that you want to store for future use when the growing season begins again in the spring. It will also work for freshly harvested seeds, however the plants that sprout from them may be more variable or unstable than typical seedlings.

Using What You Have

There are some simple household items everyone has access to such as a jar, paper towel and baggie (zipper type is best) which can be used to keep seeds fresh indefinitely.

First, grab a jar with a wide enough mouth that you can fit your paper towel inside it without any issues, although if the paper towel is slightly larger than the opening it will work too.

Seeds in a Baggie & Jar

Fill the jar about 2/3 of the way full with water and mix in a few drops of bleach, around 10-15 drops for every ~20L of water. This will kill any bacteria or other organisms that are living in the water which may be harmful to the seeds you are trying to preserve.

Grab your paper towel, it should be folded so that you have two layers and place the seeds in between the two layers.

Fold it back up and make sure everything is snug and in order. The last thing you want is for your seeds to get wet and the paper towel to fall apart while you’re carrying them from one location to another.

Make a small fold on one end of the paper towel and lay it over the opening of the jar.

Turn the jar on its side and roll up the paper towel so that it is tightly wound around the seeds, this will help to keep them from moving around inside the jar. Some water may get into your baggie but don’t worry about it.

The Rolled Up Paper Towel

Place the jar into a freezer baggie and seal it, this will prevent any more water from getting in your baggie.

Freezer Bag with Jar & Water

Label your seeds so you know what you have stored for future reference. This method can be used to store large quantities of cannabis seeds which will give you plenty of stock to pull from as needed.

You can keep this jar in the freezer indefinitely and it will remain fresh until you find a time where the growing season is once again right around the corner.


If your seeds sprout but aren’t giving you quality plants, try storing them for a little longer. If you are still having issues after that then it may be due to the environmental conditions the seeds are subjected to. Just like anything else, cannabis seeds can only take so much before they lose their ability to produce quality plants. 

This is because many of these factors harm the structure of the cells of the seed, rendering them unable to produce healthy plants. So be sure your seeds are stored in a cool, dry place with no direct sunlight and at around 60-70% humidity to maximize their shelf life.

What About if I Want to Store my Cannabis Seeds for Many Years?

If you would like to store your seeds for several years or longer, then it’s best to store them in the fridge. This will ensure that your seeds stay fresh for as long as possible, and will also help to minimize the chances of them sprouting.

If you choose to store your cannabis seeds this way, make sure they are completely dry before you put them into the freezer (water inside the seeds can expand when frozen). It’s also recommended to keep your seeds in a small, airtight plastic bag while they’re in the freezer.

Finally remember that even if you follow all of these guidelines, there’s still a chance (albeit a small one) that your cannabis seeds could develop mildew and other problems while stored for long periods of time. This now relies on one’s responsibility with the seeds. 

Why Should You Care about Keeping Cannabis Seeds Fresh? 

If you’ve been growing cannabis for any length of time, chances are that at some point in the process you will have had to buy cannabis seeds online. This is a great way to get your hands on good quality seeds from a wide range of different strains and crosses, but not all seed suppliers treat their seeds with care – and if they can’t keep their seeds fresh, then chances are they’re not buying them from good breeders either.

When you buy cannabis seeds online there’s no guarantee that they will be viable when you receive them, unless the retailer specifically states so on their website or advertises it as a feature of their seed bank. As such, it’s best to take some steps to preserve the freshness of your seeds when you get them.

Does the THC content of a cannabis strain affect the freshness and preservation of its seeds?

The THC content in Acapulco Gold cannabis strain does not affect the freshness and preservation of its seeds. The quality and viability of the seeds are determined by proper storage conditions, regardless of the THC levels in the strain. The key factor is to store the seeds in a cool, dark, and dry environment.

Buy Your Seeds from Green Nexus Today

If you are interested in growing your own cannabis, then Green Nexus welcomes you to browse through our catalog and find the most suitable choice for you. Contact us at [phone] for more information about our seeds.