How To Store Cannabis Seeds Long Term

In this How to Store Cannabis Seed Guide I will go over tips for the best ways on how to store cannabis seeds for short periods or for long term cannabis seed storage. In this how to on cannabis seed storage I will also go over the best place to store cannabis seeds whether you need to know the best method to store your cannabis seeds for days, months, or even years. I also briefly go over some tips on how to select the best cannabis seeds for your personal preferences! 
Every great strain today started from just a tiny seed. The care you put into your plants and seeds directly translates to their overall health and the quality of your end harvest, and that all starts with proper seed selection and storage. 


1. How To Select The Best Cannabis Seeds


Before we discuss storing cannabis seeds,  Remember that your cannabis seeds are a living being. Prior to germination they are in a state of hibernation, they can be viable for a long time if in stable conditions but even slight temperature and humidity variations will drastically reduce their viability over time, eventually they will die inside their shell and no longer have the energy or ability to pop.  

How to Decide What Cannabis Seeds are A Best For You? 

Getting good reputable info on growing your own cannabis can be challenging. As many businesses develop cutting edge strategies they often tend to want to keep the secrets to themselves but as you know i find it important to share with the community so we can all be better. As says In one of their articles on the Ultimate Guide to Feminized Marijuana: how to find the perfect strain  “The abundance of options available can make the selection of the right feminized seed an overwhelming task”. It is  important to do as much research as possible and keep record of what strains you have the best interactions with in order to  find the best cultivars that suit you for your specific needs. I prefer a mix of all the range cannabis has to offer throughout different times of my day.  

How to store your cannabis seeds.



Your goal with storage is to ensure the seeds will have high germination rates  for when the time comes you are ready to sprout them. Since the seeds are a living being, you need to maintain certain conditions or their shelflife will be reduced drastically. Even though seeds have a hard shell and are fairly resilient, they can also be fragile in improper storage so you should have the following parameters in mind to avoid most problems.




When stored in stable conditions, cannabis seeds can be viable for up to 10 years successfully. Whether you’re a home grower waiting for the special occasion to grow that unique strain you just bought or a breeder or seedbank who needs to stock seeds while they are tested for stability before release and for long term storage before sale. Whatever your reason may be for having seeds, taking care of them is one of the most important things you can do for your harvest. A badly stored seed may not germinate, and if it does it may not grow to your expectations. There are various parameters you’ll need to follow in order to store seeds long-term.


While they can be resilient, The ideal situations will help prolong your collection of Cannabis seeds.  There are three main factors that can affect seeds in a bad way:


If you’ve ever germinated cannabis seeds before, then you know that light is an important factor when it comes to the probability of the seed germinating or not. If your seeds are exposed to light for too long they may end up germinating or drying out before you're ready to plant them. UV light being the biggest enemy 


Humidity is another crucial factor for the success rate of your seeds as humidity is essentially what causes seeds to germinate. Any fridge will due but its best if you have a dry fridge or something like a wine fridge or one specifically designed for cannabis like the Curidor which i use because it  maintains proper humidity levels and holds a tighter temperature range than a typical fridge. plus it does it all more efficiently than a full sized fridge. The main focus is you don’t want them accidentally germinating, if they reach a certain humidity level they may start absorbing nutrients and end up too weak to grow normally, so you want to keep them in a relatively dry place. This obviously depends on your climate as there are places that have incredibly high humidity and others that are quite dry, which can directly impact how you have to store your seeds or what kind of equipment you might need to maintain ideal conditions. 



Beginner Tip: if youre unsure whether your seeds are fully dried or not, A good way to keep humidity low is to use silica gel sachets or some will use dry rice grains in the container with the seeds.


you would think the dryer the better, but theres actually a slightly moist window that is ideal for seed storage, since Even as low as an 8% humidity in the container can cause fungi to appear inside and outside your seeds, at 40-60% your seeds will sprout and beyond that, they can drown in less than a day. Let's quickly run through all the possible scenarios at different humidity levels:

  • 81 - 100% - Seeds will not survive more than 12 hours, and could drown in less than 4 hours.
  • 61 - 80% - Still a high risk of your seeds becoming inactive, with the possibility of them dying in less than 12 hours
  • 31 - 60% - This is the accepted germination range, although many cultivators prefer a 40 to 60% range
  • 21 - 30% - this is the ideal storage humidity range for cannabis seeds
  • 9 - 20% - If seeds are left for longer than a day or two at this humidity level, they are at risk of becoming a breeding greyhound for a range of non-beneficial fungi. This fungus can kill the seed in less than 12 hours once it takes a proper foothold
  • 0 - 8% - This is the perfect humidity range for pests and insects to wreak havoc on your seeds


The temperature at which you store your seeds is quite important. You’ll need to store them at around 6-8 celsius 42-47 while cannabis prefers around 10-11 C or  50-52 F or ( You can keep them in your home fridge, curidor or even your freezer (however it’s usually not necessary to freeze them unless trying to hold on to them for 5-10 years or more)


The best temperature to store cannabis seeds depends on your intended time of storage.

The best place to store cannabis seeds depends on the desired length of storage but ideally would be in a sealed insulated packaging and inside a fridge or even a freezer that wont be opened too frequently. I recommend storing them in the vegetable drawer or far back in the refrigerator and using a small cooler or something similar so the temperature doesn’t oscillate when opening the fridge door or if the power goes out. A small insulated lunchbox or insulated shopping bag are great for this whether using a home fridge or a Curidor. A good general rule is that the lower the temperature that you store those precious little beans of joy, the longer they will last, and the less chance you have of unexpected germination. However too low of a temperature will make them very fragile and small vibrations could then easily damage them so there is a window that seems to work best for home growers unless you have a stable deep freezer specifically for hash and these purposes. Growers who like to play with strain genetics and produce their own cross breeds through seed creation will usually have a special, dedicated fridge or freezer that they only use for their seeds such as the Curidor I use because its much more consistent and it only is opened to retrieve seeds or cannabis i put in for long term storage. 

If you are using your normal fridge/freezer for seed storage there are a few key things to keep in mind. First up, seeds are super light sensitive, so however you choose to store them, make sure they are in a light sealed container or insulated bag or lunchbox like i meantioned. It's also good to ensure that your fridge or freezer has no frosting issues (as many older models will frost over without regular maintenance). This can lead to moisture being released if the temperature dips, which is not what you want if your seeds are stored there. If you have access to a vacuum sealer, then we recommend using it to first seal the seed fully - if you don't then a snap or zip lock bag will do fine. Then put the bag inside a light-proof container

Storing cannabis seeds at low humidity levels in a dark place is a great way to maintain good germination rates. But one of the best ways for preserving cannabis seeds is to use low temperatures. At low temperatures cannabis seed life is greatly extended. This is because the delicate living plant tissue inside the seed can survive for much longer periods at cool temperatures which slow down the cellular biochemistry. It’s the same reason that food lasts longer in the fridge than it would at room temperature.

Most people use temperatures of around 4ºC (39ºF). But 4ºC isn't a magic number. If you can ‘only’ store your cannabis seeds at e.g. 10ºC the seeds will last longer than they would stored at 20ºC. Storing cannabis seeds at 4ºC will allow longer seed storage than 10ºC.

but the ideal range isnt freezing as remember your seed is alive and freezing temperatures can harm the embryo, 

Storing cannabis seeds in the freezer (-15 to -20ºC) is possible and this allows even longer term seed storage. However this does come with many risks. When stored at freezer temperatures you can expect cannabis seeds to remain viable for decades. The very low temperatures effectively allow the seed embryo to survive for long periods. But even heavy vibrations or disturbances can disrupt their embryos in this stage. 

Cannabis seed companies such as Dutch Passion store their archived seed collection (1970’s & 1980’s) in the freezer. This allows long term storage. However, it also comes with certain risks. In the freezer, the delicate frozen tissues in the seed embryo can shatter if the seeds are mishandled or shaken. That’s why the freezer is only recommended for those placing seeds into very very long term storage. For most home growers, the fridge (4ºC) is a great place for storing cannabis seeds.

but if you have total control, or the ability to get something like a curidor, then 6-8 C or 43-47 is the ideal range, i set my curidor to 45 degrees F (7 C) 



If you’re storing seeds for a couple of weeks it’s okay if you leave them in the original package as long as they are in a dark, dry, and cool place. A fridge isn't necessary in this circumstance especially if you plan to pop the seeds within several weeks of getting them. Ive actually had seeds last for years just in my bedroom conditions prior to getting the curidor, but i wanted to ensure longevity for my new creations and a dedicated fridge is small fraction of the total worth of a seed collection, so its a worthy investment. 



Storing cannabis seeds in the original container is usually best practice especially for short term storage
   Usually, the package they come in is light-proof and water-resistent, as long as you leave them in a relatively cool place like a drawer or something similar they will be good for several weeks or more, even better if you have them in a a safe or an insulated bag that will  make temperature swings less drastic. 


If you’re storing your seeds for several months or more it is better if you store them in the refrigerator. This will guarantee the seeds don’t suffer from temperature swings. By keeping them in their original package or in a light-proof container you ensure they will be good for as long as you need. 


This usually applies to seed banks or breeders. If you need to store seeds for a really long time you can store them in a freezer but a dedicated fridge and some insulated bags can be just as effective. although not completely necessary, the combination of a fridge and an insulated bag prevents your seeds from feeling the oscillation of temperatures even when you open the fridge to grab some of your stash. It all depends on what you prefer and what options you have available. Ideally, you want to store your seeds in a cool, dark, and dry place. When storing seeds in the fridge or freezer you can add silica gel sachets to ensure they’re completely dry. Remember high  humidity can cause them to germinate unintentionally or trigger fungi to grow on your seeds or cause them to. If your seeds get exposed to light or rapid changes in temperature it will trigger them to use up their nutrient stores before they ever see soil, meaning they won’t have the nutrients they need to germinate when you want them to. 




There is a handy, simple test to check if your seeds are bad similar to a bad egg test. Just drop them in a cup of water (only once you are ready to actually germinate them). If they sink to the bottom and stay there then they are healthy and ready to be used. If the seeds float then there is a pretty high chance that they are not going to germinate. Don't throw them out just yet though, give them 3 days or so to see if they do sprout a tap root. There are a couple of common methods used to germinate cannabis seeds. Let's quickly run through them, starting with our favorite germination method to our least favorite.


This method is simple, straightforward, and is the method of choice for most home growers. All you need is:

  • A few paper towels (unperfumed and uncolored best if theyre natural as possible)
  • Water that has a pH of 5.5 to 6.5 and at a temp of 22C or so
  • A spray bottle
  • Your cannabis seeds
  • A plate and plastic wrap, a plastic bag, or resealable container

Wet one of the paper towels and give it a light squeeze to remove any excess water. Lay it down flat and place 2 to 3 seeds onto it, with a spacing of about 2 centimeters between each seed. Then all you have to do is wet another paper towel, ring it out slightly, and place it on top of the seeds. Once this is all done place the envelope into the  container, and store the seeds in a dark, warm area.

 The paper towel method is the most common choice amongst growers and while there are benefits of the seed contacting soil directly from the beginning i prefer to know exactly what seeds have popped before placing them in the soil, so that i dont waste any space. i have almost never had a seed not pop above soil after i planted it from a paper towel germination. 


 This method should allow the seed to germinate in 2 to 3 days. Check the seeds every day, and if the paper towel is starting to dry out then give it a light spray with your pH water, after 3-4 days you should have 100% germination, if popping okder seeds some will scrape the outer shell to help them pop easier ir place in hydrogen peroxide to soften them up, if after 3 days it hasnt popped ive also seen breeders like capulator just physically very carefully squeeze the seed and crack the outer shell while being careful not to crush the embryo inside and if done carefully enough then this works as well. if after a week you still have some that havent germinated  or something went wrong, they either got too hot, too cold, or they werent stored properly. Please consider your own mistakes before trying to blame the breeder. 


This method is just as easy and straightforward as the paper towel method. The only reason it's not number one on the list is that it requires the use of Rockwool, which is not as easily available for everyone as paper towels. And i prefer not to have a block of rockwell trapped in my roots as i then will have to remove it later before i can compost my weed stems when i harvest.  The list of needed items is:

  • Water that has a pH of 5.5 to 6.5 and at a temp of 22C or so
  • Rockwool cubes
  • A spray bottle
  • Cannabis seeds
  • A container as mentioned in the paper towel method 

So, why is Rockwool a preffered germinating medium by many growers over paper towels? First up, paper towels are sometimes fragranced or colored. This is not good for cannabis seeds, so its best to get undyed and unbleached organic paper towels, with Rockwool, you don't need to worry about this at all. Rockwool also has great water retention properties, meaning you will not need to re-wet it as often as you do with a paper towel. It also provides a great home for your baby plant for the first 2 weeks or so, which gives you more time to get your growing medium set up. First up, soak the Rockwool cube overnight in your Pho -adjusted water. Then just drop your seed into the opening on the top of the cube, and place the whole thing in a sealed container. You should see the tap root after 24 -72 hours.




, there are a bunch of cannabis cultivators out there that love this method of germination, and yes it will work in most instances. But, in my experience, the rate of germination is not as high as the previous 2 and i dont prefer this method cuz its too “sloppy” to me to have all the seeds floating and getting tangled together. It is the most simple method though. All you need to do is drop your seed (or seeds) into a glass of pH-adjusted water and let nature take its course. Be very careful when transplanting the seed to its growing medium. Of course, you can just plant the seed directly into your soil or coco-coir - but this makes it much harder to check on the progress of the germination. There are also a bunch of targeted products for seed germination on the market. These work well but are usually pretty high priced. Why drop a bunch of cash on a piece of equipment when a paper towel, a container, and some ph adjusted water will do the exact same thing. You can also do a few key things to help your seed germinate quickly, especially if they are old seeds that haven't been left in ideal conditions.


  • Using finer-grade sandpaper, softly and gently score the outer shell of the seed. This helps the germinating moisture to penetrate the shell, which becomes tougher the older the seed is.
  • If the outer shell is really thick and tough you can use a super sharp knife or even a scalpel to make a small incision in the shell.
  • Carbonate water can help with germination, as can adding fulvic acid, or hydrogen peroxide to the water before soaking or spraying the seed and that's it!

To learn about making seeds and pollen storage or to grow your own organnabis check my other articles and youtube! 

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