Storing cannabis seeds in the right conditions allows you to preserve your favourite cannabis genetics for many years. Store your seed collection safely! How do you store cannabis seeds so you can use them for future use? Learn how to properly care for your seeds so you can grow the best plants. There’s a lot of reasons to store cannabis seeds rather than just planting them in soil and letting them do their work. Whatever the reason, you need to be sure those cannabis seeds stay viable in the long term. Click here to learn how to properly store your seeds until your ready to plant!
How to store cannabis seeds the right way
Storing cannabis seeds under the correct conditions allows you to preserve your favourite cannabis genetics for many years. With the right conditions you can keep the best part of your cannabis seed collection viable for a decade or more. But get the conditions wrong and the germination rates on your best-loved feminised seeds and autoflower seeds will suffer. If you are a cannabis seed connoisseur that spends time, cash and love building a collection of the best cannabis genetics then it makes sense to learn more about storing your cannabis seeds under ideal long term conditions.
Did you know cannabis seeds are living organisms?
When preserving cannabis seeds, it’s worth remembering that seeds are technically classified as living organisms. That’s because they have an embryo which is capable of being germinated and growing into a new plant. Just like any other seed, environmental conditions for storing cannabis seeds can be fine tuned to maximise seed germination rates. But provide the wrong conditions for storing cannabis seeds and your seed germination rates will decrease rapidly. Storing cannabis seeds till germination under ideal conditions is the best way to maximise germination rates.
Key factors to watch when storing cannabis seeds
When storing cannabis seeds there are three main issues which will reduce the germination rates (or the ‘viability’) of your cannabis seeds. These are light, heat and humidity. Each of these factors will reduce the germination rates of your autoflower seeds/feminised seeds. Conversely, if you can minimise and correctly control heat, light and humidity then you will extend the lifetime of your cannabis seed collection.
Inside your cannabis seeds are delicate embryonic tissues which store the genetic code. This, in turn, defines the type of cannabis you will eventually grow. When storing cannabis seeds long term, keeping the seeds away from bright light is important – don’t store them in your grow room! A sealable, light proof container is ideal.
The shell of the cannabis seed does help to protect the embryo from light. But remember, in nature, cannabis seeds were normally dropped from the plant onto the soil in autumn/fall. There they would remain under a light covering of soil until they germinated the following spring. Cannabis seeds were never designed to cope with intense light levels. Storing cannabis seeds in the fridge, in a dark humidity proof container is a good way to maintain maximum seed germination rates.
Dutch Passion cannabis seeds can be stored simply be re-sealing the seed packet with tape and placing it inside the seed tin or a container. Storing cannabis seeds in eppendorf tubes (black or amber) in the fridge is a popular technique. Eppendorf tubes are small plastic tubes normally used for storing liquids, but they are often used for cannabis seed storage too.
When storing cannabis seeds, humidity levels are an important factor. In order to germinate cannabis seeds, moist humid conditions are used. So it makes sense to use low humidity conditions for cannabis seed storage. You certainly don’t want to store your seeds anywhere where moisture droplets, which will soften the shell. Water/moisture is a very effective way to soften the hard, rigid shell of the cannabis seed. This allows the tap root to emerge.
When storing cannabis seeds for the long term, the actual water content inside the seed will be around 10%. Storing cannabis seeds in the refrigerator is an easy way to maintain the low humidity levels that suit long term seed viability. Just make sure that your seeds are stored in a dark, dry container without any condensation near the seeds and you should be able to store cannabis seeds in the fridge for perhaps 5 years or more and still have good germination rates.
It’s not necessary to measure humidity levels in your fridge. Just ensure your seeds are in a sealed dry and dark container inside your fridge and they should last many years.
If you have produced your own cannabis seeds you may be aware that when they are very fresh, straight off the plant, they may even be a little too fresh to germinate. That’s why some believe in storing and maturing cannabis seeds for a short period at room temperature. This allows moisture content of the seed to drop enough for the seeds to become more viable. How long to let seeds dry before storing? A couple of months at room temperature should be sufficient.
|Humidity levels||Effects on cannabis seeds|
|75% to 100%||Humidity is too high, causing seeds to have excessively high internal moisture content which decreases long term germination viability.|
|25% to 75%||Good for cannabis seed storage, especially at low temperatures in sealed/dark containers.|
|0% to 25%||Too dry, seeds may desiccate (dry out excessively) especially if they were not in a sealed humidity proof bag/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.
What is the ideal storage temperature for storing seeds? 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.
Storing cannabis seeds in the freezer (-15 to -20ºC) is also possible and this allows even better seed storage. However this does come with some 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.
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 long term storage. For most home growers, the fridge (4ºC) is a great place for storing cannabis seeds.
So what are the best ways to store your cannabis seeds?
What is the optimal temperature for storing seeds? For most people, temperatures around 4ºC (in the fridge) are perfect. If the autoflower seeds/feminised seeds are in a sealed lightproof container they are automatically at a low humidity and in a dark place.
Don’t worry too much about keeping your seeds in a fridge at all times. Remember that even without a fridge, a pack of seeds stored in a draw for a couple of years should still show good germination rates. Avoid storing your seeds in places with high temperatures or intense light, such as a window ledge or your grow room.
If storing cannabis seeds in a sealed plastic bag in the fridge remember that they are easy to accidentally crush if something is placed on top of them. A small box or plastic container can prevent that.
Should I date my seeds when storing them?
It’s probably not necessary for most people but it could be a useful guide for later germination.
How long can you preserve cannabis seeds?
In the freezer you can store cannabis seeds for decades. In the fridge, you should see good germination rates (50% or more) even after 5+ years. Without using the fridge, germination rates start to decrease earlier and faster.
If you usually germinate your cannabis seeds within a few weeks/months of purchase you may not need to worry too much about how to store them.
When cannabis seeds are supplied from the seed supplier, germination rates should be 90% or higher if you are buying from a proven supplier. Even after 5 years in the fridge you should still expect the majority of your cannabis seeds to germinate.
This is good news for those growers that have found the ideal cannabis seeds for their needs and want to ensure a viable seed collection of their favourite cannabis genetics for many years to come.
Drying, storing and maturing seeds from plants
Although not many growers can be bothered with the hassle of producing their own cannabis seeds, if you do attempt to produce seeds it’s important to know about maturing them.
When drying and storing and maturing cannabis seeds one of the main tips is to allow the fresh seeds time to rest before germinating. Fresh seeds haven’t had the natural time period required to allow them to reach maximum germination rates.
Typically seeds of various plants store better, and germinate faster when they have dried a little after the seeds have been collected. After a month or two in ambient conditions, the seeds have matured and should show higher germination rates.
What size mylar bags to use for storing marijuana seeds?
Size really doesn’t matter! Just ensure your seeds are sealed, safe from light/moisture and stored at low temperatures.
What if you found an old undated bag of seeds?
Whether you are preserving seeds of F1 landrace cannabis genetics or any other type of cannabis seeds your best chances of storing them is at low temperatures in dry and dark conditions. Many growers collect extensive (and expensive!) cannabis seed collections.
Dating each seed packet is a good idea, although it won’t improve germination rates it will give you an idea of the age of the seeds. Even after 10 years in a fridge at 4ºC you can still expect to see a some of your seeds germinate, assuming they original seed quality was high.
If your cannabis seeds are really old, some growers may suggest a few unusual tips to increases germination. Dutch Passion can’t really recommend these techniques, they simply carry too much chance of damaging the seed. These techniques include gently sandpapering the outer layer of the seed shell, perhaps including the ridge down the side. The logic here is that particularly old/hard seed shells need assistance to open.
Dutch Passion prefer to stick to proven, established seed germination techniques that should work well for most people. The best way to germinate cannabis seeds is to do so between a couple of lightly moistened cotton pads for a couple of days.
How to store cannabis seeds
Want to know the best way to grow the best marijuana? Start with great seeds. But once you find the perfect strain, how do you store seeds so that you can use them for future plants? It’s not that hard; actually, you just need to keep them cold, dark, and dry. However, there are few other things that you could do to preserve your precious seeds – keep reading to learn more.
A guide to storing marijuana seeds
If you plan to grow marijuana for fun or profit, you’ll need to know how to store your seeds.
Why is storing cannabis seeds important?
Those seeds are directly related to the quality of your plants. If they are not stored correctly, when you do get around to planting them, they will not germinate. On the other hand, if you store them the right way, they are good to go indefinitely.
Some growers keep seeds for years. However, it’s common to leave a few seeds in storage for less than a year, especially when there are limits around how much you can grow at one time. There’s no reason why those extra seeds should go to waste, simply learn how to store them correctly.
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Use the right storage container
When storing cannabis seeds, the first thing to think about is your container. Do not use just any random container that you come across. The ideal container should be made of one material.
Avoid containers with a mixture of materials. An example of this would be a plastic container with a metal lid or a glass container with a plastic cover. Containers made from more than one material react differently to temperature and other changes, and this can create room for undesirable conditions to reach your stored cannabis seeds. For instance, the metal lid on a glass jar will expand at a different rate when the temperature rises, and this may allow some moisture to enter the container.
Many people suggest using plastic containers for long-term storage when asked how to store marijuana seeds, but that isn’t a great idea either. Plastic has tiny (microscopic) pores that can let air infiltrate the container and damage your seeds. If you want your seeds to last, don’t store them in a plastic container. Glass is a much better solution.
Label the containers
Chances are you are storing more than one strain of cannabis seeds. Even if you are storing just one variety of seeds, you must label the container. Otherwise, if you store the seeds for years, you may forget which strain they are and that they are even marijuana seeds!
Keep light out
This part is simple; germination needs light. If you do not want your seeds to sprout, keep the light out. That’s why the most immediate answer to “how to store cannabis seeds” is “keep the environment light free.”
Want an easy way to keep light out?
Try using an opaque container. If the glass jars you used aren’t opaque, then place your seeds in something opaque, such as a black plastic wrap, then put that in the glass jar. Again, keep in mind, plastic is not the best for long term (years), but if you are purchasing at the end of one grow season in preparation for the next, it should work just fine.
You can also place your cannabis seeds in a fridge that doesn’t get opened much or another dark location.
Keep the temperature constant
Another thing that you need to think about when storing cannabis seeds is to maintain a stable temperature. Try and keep the seeds around 40° Fahrenheit. You do not want them to freeze.
Many people do this by keeping their seeds in a fridge or freezer. (Again, do not allow the seeds to freeze.) The most critical thing is keeping that temperature constant. Your marijuana seeds can deteriorate when the temperature fluctuates.
Keep moisture out
Moisture is the other condition that is required for germination, so you’ll need to keep your seeds dry as well. Depending on how much moisture your marijuana seeds are exposed to, they could either germinate or even rot while in storage.
For the best results, keep moisture levels between 5% and 9%. An airtight, sealed container is a great way to do this. You could also add something to help absorb any moisture, such as silica packets or even uncooked rice.
If you decide to use one of these methods, make sure you use something food-grade. Remember, this material will be sitting in storage next to your seeds. It’s also a good idea to use some sort of barrier, such as some cotton wool, between your moisture-absorbing packs and the marijuana seeds. This will leave the seeds undisturbed while the moisture problems are addressed.
Keep the storage environment clean
How to store marijuana seeds properly also means keeping the storage environment clean. If you’re not careful, pests can quickly destroy your cannabis seeds if they access the storage container and its contents.
A clean environment also keeps other contaminants, such as microbes, from compromising the quality of your seeds. After all, you will eventually plant those seeds, and you don’t want to consume cannabis grown from contaminated seeds.
Nature-designed seeds to last until the ideal germination environment occurs. Therefore, if you follow these storage tips and prevent that environment from happening, you could store cannabis seeds indefinitely.
Does it need to be perfect?
No. If you only need to store cannabis seeds for a few months, you don’t need to be that strict. However, if you’d like to keep your seeds for years, plan ahead and take the necessary precautions, and you’ll be delighted that you did.
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How to Store Marijuana Seeds Properly
T here’s a lot of reasons to store marijuana seeds rather than just planting them in soil and letting them do their work. Sometimes you have some seeds leftover from your new favorite weed strain and don’t have the space available where you live to plant it. Other times, you’re buying seeds for later use once you’ve got the time and energy for your weed growing project. Maybe you’d like to hold on to precious genetics until you can seek out another strain to cross it to. Sometimes you’re just stocking up for an uncertain future.
Whatever the reason, you need to be sure those marijuana seeds stay viable in the long term. Properly stored marijuana seeds can last for up to five years and still remain viable, and some strains have been reported sprouting at ten years or more.
However, proper storage is not as easy as it seems, since seeds are looking for any excuse to start sprouting and there are a number of factors that tell the seeds that the time is right to stretch out their roots and branches. Store your marijuana seeds in the wrong conditions and they might end up dead, rotting, or diseased by the time you’re ready to introduce them to the soil.
Fundamentals of Marijuana Seed Storage
First, let’s go over the five main factors to consider when it comes to how to store marijuana seeds, especially for the long term.
Keep Your Marijuana Seeds Cool
When it comes to preserving your marijuana seeds for future planting, temperature is the main consideration. In nature, heat is what tells the seed that the winter’s over, which means that it’s time to break open and start sending roots down and shoots up.
If your marijuana seed is not in the soil, this means that the plant matter inside the seed will begin to germinate. The shell will crack open, letting the plant matter out and moisture, bacteria, and pests in. Without soil to thrive in, the marijuana seed will begin to rot.
41℉ (5 ℃) is the absolute warmest you want your long-term storage spot to be, with the sweet spot being somewhere around 38 ℉.
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It’s very important that this temperature remains stable for the long term. If you are refrigerating your marijuana seeds, your best bet is to place them in a separate unit or a spot near the back. Every time that you open your fridge the temperature fluctuates, which can harm the marijuana seeds over time.
While it’s up for debate whether freezing marijuana seeds is an effective method for long term storage, we don’t recommend it unless you know exactly how to cure and prepare your seeds. Otherwise, the frozen water in the seed’s cells can expand, destroying the cell wall and killing the seed.
Watch out for Humidity
Humidity is another enemy in your battle for storing cannabis seeds long-term because any hint of moisture is another clue to the seed that it’s time to stretch its leafy arms and legs. If the marijuana seed shell breaches before it’s in the soil, rot can set in.
However, you don’t want your marijuana seed too dry either. A humidity level of about 5% is the maximum that you want to allow in order to keep the waxy, protective layer surrounding the seed intact without triggering the seed to split open.
Store Your Marijuana Seeds in an Airtight Container
Besides being dark, you want to expose your marijuana seeds to as little oxygen and carbon dioxide as possible. These gasses are what growing plants breathe, as well as the pests that consume them.
If you’re storing cannabis seeds by refrigerating them, make your container as airtight as possible. If you have some vacuum-sealed plastic on hand, even better.
Keep Your Marijuana Seeds in The Dark
Much like heat and humidity, light tells that marijuana seed to wake up because it’s time to spring forth. Even if it’s a halogen bulb inside your refrigerator and not the sun itself, the seed’s natural optimism can still start the flowering process.
Light exposure over time can also damage the surface of the seed, which in turn will damage what’s stored underneath. The solution, much like storing cannabis flower and other products, is to keep your marijuana seeds in a dark or opaque container. Without exposure to light, they’ll keep dozing long term.
Your Marijuana Seed’s Genetics
Some weed strains (and some specific batches of those strains) naturally produce seeds that are hardier and longer-lasting than others. This plays a role in how long you can expect your marijuana seeds to remain viable, so be sure to do some research beforehand.
Storage Methods for Marijuana Seeds
Now that we’ve covered how temperature, humidity, light, air, and genetics work against you when it comes to seed storage, let’s cover the best marijuana seed storage methods.
If you’re storing your marijuana seeds for the short term (a couple of weeks or months), a standard mailing envelope or a tan coin envelope will do in a pinch. If the envelope paper is thick enough, it will protect the seeds from the most harmful ambient light. If the envelope is stored in a cool, dry, dark, and temperature-stable spot like the back of a closet or a drawer, the marijuana seeds should also stay dormant in the short term.
Plus, an envelope makes it easy to write the name of the weed strain, the date of storage, and any other important notes you have. If you want to be extra safe about it, throw some grains of rice or a desiccant pack in there to regulate the humidity.
Of course, this method is only as good at the stability of your home’s climate. If you live in a humid area prone to frequent storms or weather fluctuations like Florida, envelopes will only get you so far without ruining your marijuana seeds.
Unlike a mailing envelope, glass jars are airtight, which makes them much more suitable for storing cannabis seeds long-term. Because many types of plastic can let small amounts of water in overtime, it’s highly recommended that you use glass with rubber stoppers. When storing cannabis seeds long term, you should also throw in a desiccant pack to keep the humidity stable.
Be sure to separate the pack from the marijuana seeds with a couple cotton balls or a paper towel. This will help absorb excess moisture at the start as well. If you have a method to vacuum seal the jar even better. Wrap the jar in something opaque and you’re all set. Marijuana seeds stored at a stable room temperature can last for over a year. Refrigerated they can last a couple years.
If you’re looking to store your cannabis seeds long term, vacuum sealing your seeds in thick Mylar bags can keep your seeds viable for up to half a decade. Because the bags are designed for long-term storage, they’ll work well for your marijuana seeds as long as you make sure they were stored at the right humidity (again, a desiccant pack helps with this) and away from the light. This is one of the best options if you’re refrigerating marijuana seeds.
Seeds of Wisdom
In conclusion, storing cannabis seeds for the long haul is relatively simple. They will stay viable as long as they’re kept away from heat, light, moisture, and air. The more care you put into your storage method, the longer your marijuana seeds will last. However, when it comes to planting marijuana seeds with the most chance of success, sooner is always better.
What are your best methods for storing seeds? Share in the comments below!