How long do marijuana seeds last?
And how to store them
If you’ve read our previous article on why you should grow your own marijuana, you learned that growing your own weed is fun, cheaper in the long run, and a sure way to never run out of something to smoke.
If you, like yours truly here are suffering from FOMO (for the non-hipsters among us: that’s short for “Fear Of Missing Out” 😉 and subscribed to a plethora of newsletters from various seedbanks to never miss out on a solid bargain, a certain luxury problem could occur: What do you do with all these newly acquired treasures when you don’t have an immediate use for them?
While nothing lasts forever, along the way I’ve learned that, if stored properly, marijuana seeds will remain viable for quite some while. With this article, I hope to finally answer that frequently asked question: how long do marijuana seeds last?
- How long do marijuana seeds last after storing them?
- How to store marijuana seeds
- What is the best place to store your seeds?
- Where do you keep your seeds in?
- Are there disadvantages of old seeds?
- How long do marijuana seeds last? let's recap.
How Long do marijuana seeds last after storing them?
The short answer is several years or up to 5 years, depending on the circumstances.
The fact remains, that seeds exceeding that storage period are significantly harder to germinate.
So, you’ve scored big during the annual Black Friday sale and stocked up on all your favorites but then you remember, planting is months away.
Make sure your bargain isn’t going to cost you and ensure the viability of your seeds when planting time arrives with proper seed storage. It doesn’t take much, especially if you are storing seeds short term (less than two years).
If you plan to store your seeds for longer, it requires a few more steps to protect the long-term viability of the seed. But for short-term storage, a cool, dark, and dry spot are all you need.
Mother Nature’s designed them to respond to their environment within particular heat and moisture to signal the seed when it’s time to germinate.
Which, in nature is key to the survival of the plant, but not so convenient if you don’t have the intention of using them right away.
How to Store Marijuana Seeds
Marijuana seeds are living organisms which, when correctly stored, remain dormant. All seeds need to germinate is humidity and temperatures that are favorable.
Make sure your seeds don’t prematurely sprout by storing them in a spot that doesn’t have the right humidity levels and ensure the seeds are dry before sealing them in a container
Key factors for your storage conditions environment
- Humidity: Moisture is an especially important factor if you are freezing or refrigerating your seeds. If seeds are too wet, they can rot in the refrigerator or crystallize and suffer frost damage in the freezer. If you store seeds in the refrigerator or freezer, place the packets in an air-tight container and ensure you’ve properly dried the seeds, to begin with. As Cannabis expert Ryan Riley explains in Ryan Riley’s Growing Elite Marijuana
- Temperature: Consistency is key when it comes to temperature. So, you should avoid storing seeds in a spot that isn’t climate-controlled, like a garage or shed, where temperature can fluctuate wildly, especially during summer. 6 °C or lower would be ideal in terms of temperature. Unwanted fungi and bacteria in and on the seed may otherwise build up rapidly in a moist environment. High moisture levels and high temperatures will kill cannabis seeds as quickly as an invasion of microorganisms and insects, so be careful. How long marijuana seeds last, mainly depends on each 41°F / 5°C) temperature reduction in the storage environment. The recommended temperature is at least 41°F /5°C) (yes, this is slightly warmer than regular fridges). The cooler the temperature the more slowly seed vitality declines. This rule apparently continues to apply even at temperatures below freezing. At 41 °F (5 °C)
- Light: is necessary for germination; over-exposure may bring seeds to come out of their dormant state and encourage them to mutate. By keeping them in the darkness you ensure that they will remain dormant (provided that you’ve also taken the other requirements into account of course).
When you meet the above-storing conditions, storing cannabis for five years while maintaining high germination rates is entirely do-able.
Riley also advises making sure to label the container/package with the strain name, quantity, and date of storage to make storing easier.
In our article How to germinate weed seeds, we will teach you various germination methods that can make even the Methuselah’s among seeds sprout.
What is the best place to store your seeds?
- Basement: Cool ✔ Dark ✔ That’s two out of three requirements down. As for moisture control: Experts swear by placing the seed in a closed container along with some uncooked rice to absorb any moisture (don’t forget to replace the rice regularly). A food-grade silica bag will also do the trick nicely.
- Fridge: the best option, I think is to store them in refrigerators at a temperature between 6 and 8 degrees Celsius, and with relative humidity levels between 20% and 30%. And sheltered from light, of course. This spot checks all the boxes. In regard to the best place in your refrigerator, the crisper is a good choice, as it is a little warmer than the rest of the fridge.
- Freezer: one of the most popular places to keep your stash. The average freezer is about -15 °F dark and has a minimum of temperature fluctuations. A word of caution though! Some seedbanks keep a large stock, so you are at risk that the seeds you purchased were frozen and have now thawed. When the seeds thaw, they attract moisture. Re-freezing them causes crystallization and causes the seeds to perish!
Where do you keep your seeds in?
The freezer resolves the temperature fluctuations issue since you open it a lot less than the fridge door. Freezing seeds does not hurt them and can greatly extend their lifespan if done properly. . If you are saving seeds from a seed packet where you didn’t use all the seeds, keep the packet and put it into a Ziploc baggie.
We’ve now determined that keeping them away from moisture in a climate-controlled environment and limit the exposure to light to a minimum will significantly prolong their shelf life. Keeping them in the Ziplock bag they came in seems like the obvious thing to do. Or is there a better way?
If you plan on only storing them for a few months, cannabis seeds should do fine in a grip seal bag, placed in a mason jar, or some other type of airtight container. For more long-term storage, a vacuum-sealed package is a much more popular option. Many seasoned growers like to add a food-grade desiccant or some uncooked rice to their package as well.
What about a metal box or vault? That’s a big no. The metal will kill the seeds.
Are there disadvantages to old seeds?
Even if you’re organized, methodical, and careful about storing seeds, older seeds could be more difficult to germinate, resulting in more fragile plants, a thinner stem, and require more care and attention as seedlings.
There are a few tips and tricks to apply in order to increase your chances of successful germination.
- Sandpaper method: Some breeders use sandpaper (see video below) for older seeds. Lightly and gently scrape off the outer layer of the seed, creating micro-abrasions that help them absorb moisture more easily and then soak for 12 hours.
- Hydrogen peroxide: Soak the seeds in a glass of water with a few drops of hydrogen peroxide, for 24 hours at a temperature of 28 °C. The hydrogen peroxide softens the shell and facilitates the water’s absorption.
How long do marijuana seeds last? Let’s recap.
Saving cannabis seeds is a widely used method for preserving unique genetic varieties that one has particularly enjoyed or that worked very well when planted.
The most important factors when storing your seeds are keeping them cool, dark, and dry. Maintaining a constant environment with little or no fluctuation is vital to ensure the stability of your stored seeds.
You should bear in mind that humidity and temperature are the two most significant agents to have a quality storage system of marijuana seeds. Indeed, marijuana seeds are susceptible to their surroundings, since they dry out easily in a dry atmosphere and absorb moisture in a humid area. In every 1% reduction in the confined moisture, the life of the cannabis seeds inside the container in also prolonged.
So, there you finally have your answer as to how long do marijuana seeds last. Properly storing your seeds takes a little more effort than one would think but I ensure you, that extra care will pay off.
What’s your preferred way of storing your seeds? I’m interested in hearing your thoughts!
Educated by one of the best breeders in the Netherlands, I chose to combine my passion for writing with the fascinating world of cannabis cultivation. What are the best strains for which occasion, what are the effects, and how to use responsibly? Let me take you on a journey.
Do Cannabis Seeds Go Bad?
M any pot fans are starting to look into growing their own supply. After all, how hard can it be? Nature does it all the time, and it doesn’t even have any grow light options other than the sun. While you may not be producing showroom quality nugs, there’s a pride that comes with tending to your own garden and snipping buds straight off the branch. Plus, you can’t beat the price.
Plenty of online stores sell seeds so it’s pretty easy to pick your favorite strains to start. However, if it’s been a while since your seeds arrived and they’re not yet planted, you can forgive yourself for wondering if maybe you’ve waited too long. After all, how long do marijuana seeds last? Whether you are a cannabis fan who has just begun growing a couple of plants recreationally, or you are looking to test your green thumb for the first time, there is one question that’s going to come up at some point.
Do Marijuana Seeds Go Bad?
First off, marijuana seeds are the same as many other plant’s seeds. A waxy outer shell called the seed coat protects the embryonic shoot, stem, and root contained within, which are nourished by a nutrient-rich oil surrounding them. As long as the shell remains intact and the plant inside doesn’t dry out or get damaged, your seed can still grow into a cannabis plant.
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However, this shell will not last forever. Once it dries out and hardens the seed coat can crack and expose the embryonic plant to damage. Or the seed coat hardens to the point that it no longer lets in moisture. In both cases, the seed is no longer viable.
Of course, there is some debate in the cannabis community over how long do marijuana seeds last. Some growers claim that when stored in the ideal conditions, marijuana seeds can last anywhere from six months to a year after packing and still spout once placed in the soil. Other producers believe that marijuana seeds can last up to a decade if properly refrigerated in the right containers.
Most seed producers agree that on average three to six years is a maximum for viability, and every day that the seed is stored drops the chances of it germinating just a little bit.
So how long do marijuana seeds last? In general, six months is the maximum if you’re looking for a nearly 100% germination rate. After three years, you’re looking at a germination rate of around 50%.
What constitutes “ideal conditions” for cannabis seed storage also depends on the genetics of that particular plant. Some cannabis strains produce a much hardier, longer-lasting marijuana seed that can last for years and still stretch their leaves once planted. Others produce seeds that need to quickly return to the soil.
How Marijuana Seeds Are Stored
In terms of long term storage for your marijuana seeds, there are four main factors to consider:
When it comes to how long marijuana seeds last, temperature is the main factor. In nature, heat tells the seed that winter’s over and it’s time to start sprouting. If your marijuana seed’s not in the soil, this means that the plant matter inside the marijuana seed will begin to germinate and then rot.
41 degrees Fahrenheit (5 degrees Celsius) is the absolute warmest you want your storage spot to be, with the sweet spot being somewhere around 38 degrees Fahrenheit.
If you are refrigerating your marijuana seeds, they’ll last the longest in a separate unit or a spot near the back. Every time you open your fridge you are changing the temperature which can harm the seeds over time.
Humidity is also your enemy when it comes to how long your marijuana seeds will last. When a seed gets wet, it cracks open to allow the sprout and root out. This will let in rot if the seed isn’t planted. A humidity level of about 5% is the maximum you want to allow.
Much like heat and humidity, light tells that seed to wake up because it’s time to spring forth.
By keeping your seeds in a dark or opaque container, they’ll keep dozing long term. Light can also damage the surface of the marijuana seed, which in turn will damage what’s stored underneath, causing your marijuana seed to go bad.
Besides being dark, for your marijuana seeds to last long term, you want to expose them 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 refrigerating or freezing your marijuana seeds, make sure your container is as airtight as possible. If you can vacuum seal them, even better.
Alternatively, if you’re planning on planting in the next few months, regular mailing envelopes will do in a pinch. They’ll keep the marijuana seeds out of the light and dry, so all you have to do is store them in a cool place. Plus, envelopes make it easy to label your strains so that you can keep them separate.
How To Tell If Your Marijuana Seeds Are Still Healthy?
What should you do if you find some old seeds and have no idea how long they were stored? Maybe past you put them in a freezer bag in the hopes of keeping your favorite strain alive, or found a couple at the bottom of a baggie that the trimmer missed.
How do you know if your marijuana seed has gone bad, or if it’s healthy and viable to grow into a plant? There are four easy ways to check if your marijuana seed is still good.
If your seeds are dark brown, black, or gray, that’s a very good sign. The shell is intact and uncompromised, which means the genetic material inside has been kept safe.
Viable seeds should also have stripes or spots all the way around. If the seeds are white or green, they’re most likely still immature.
Check if the seed still has a waxy coating. A healthy seed should have a slight sheen to it, as though it’s been oiled. This means the seed still can retain moisture.
If the seed is still healthy, you should be able to lightly squeeze it without it crunching between your fingers. If the shell has no give and splits or splinters under light pressure, then your marijuana seed has gone bad and has no chance in the soil.
Cracks or Holes
If there are any cracks or holes anywhere on the shell, your marijuana seed’s likely gone bad and will most likely not sprout. Bacteria and other harmful lifeforms can find their way into the seed, or it will dry out.
The True Test of a Cannabis Seed
Of course, the best way to test whether your seeds will sprout is to plant them and see. If some green shoots climb their way out of the soil after a couple of days or weeks, you’ve got your answer.
Storing marijuana seeds is a great way to make sure you always have your favorite strains on hand, as well as to keep yourself stocked up on plants for the long haul. Luckily, marijuana seeds can last for years as long as you make sure your seeds are cool, dry, airtight, and out of sight. There’s no better time than now to learn a new skill, so let’s see how green your thumb can get.
How Do You Tell If a Seed is Good or Bad?
If the seed is dark with stripes or spots all the way around, has a waxy shell that doesn’t crack when you give it a light squeeze, and doesn’t have any visible cracks or holes, it’s probably still good. If there are holes in the shell, it’s dry, or especially pale, your marijuana seed’s probably gone bad.
Do Autoflower Seeds Go Bad?
All marijuana seeds can go bad, including autoflower seeds. However, by keeping your seeds at a stable 38 degrees Fahrenheit and at around 5% humidity, as well as airtight and out of the light, your seeds may last up to 5 years or more.
How do you like to store your seeds? Share your thoughts in the comments!
Seed Storage 101: How to Store Cannabis Seeds
Not all of the seeds that you purchase always end up in the ground for planting the season that you purchase them, which means the left overs require storage. However, if they aren’t stored correctly, you risk losing that seed to environmental factors that could affect your crop – or maybe it won’t grow at all. This article is about how to correctly store your seeds until next season.
So you’ve just received your latest shipment of 25 seeds from your favourite seed bank—and you only plan to plant 5 or 10 of them this season; or you’ve just finished this season’s harvest and you’d like to store the seeds you’ve collected for your next crop … Proper storage of cannabis seeds is an essential aspect of ensuring the viability of future marijuana crops.
There are two types of seed categories:
- Orthodox Seeds – these seeds enter a dormant stage and will survive drying;
- Recalcitrant or Unorthodox Seeds – seeds that will not survive drying and are susceptible to desiccation injury.
Cannabis seeds are the orthodox type, or desiccation-tolerant, and can be prepared for long-term storage without risking instability.
Key factors to consider when storing seeds are environment and container. Environment is important because moisture levels, temperature, and light exposure all play a role in the stability of your seeds, along with oxygen and ethylene concentrations. The container you choose for storage plays an important role in that the proper environment will be maintained if you use the proper receptacle. Hand-in-hand, these factors help ensure the viability of your seeds for either long- or short-term storage periods.
Environmental factors that affect the viability of cannabis seed are:
- Moisture – reducing moisture exposure ensures seeds won’t prematurely germinate or become mouldy.
- Temperature – fluctuations in temperature can lower a seed’s longevity significantly.
- Light exposure – light is required for germination; over-exposure may cause seeds to come out of their dormant stage and encourage tissues to mutate.
- Ethylene concentration – ethylene is an important natural plant hormone; seeds begin to produce ethylene immediately after exposure to water or moisture (another reason low moisture conditions are necessary during storage).
- Oxygen concentration – lowering oxygen exposure will reduce or prevent seed respiration during storage, thus deterring premature germination.
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It is important to dry your seeds gradually and thoroughly before storing them—although not to 0% moisture, as this can result in the death of a seed. During ripening and drying, cannabis seeds will prepare for dormancy by slowing or stopping most physiological processes. Ideal moisture percentage is 2-3% and can be achieved by placing a desiccant in the storage container with your seeds. (A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its vicinity (draws out water). Commonly found pre-packaged desiccants are solids that adsorb water, e.g., silica gel packs. These can be found at Wal-Mart, Uline.com, or your local florist!). Rice is also known to be an effective desiccant, but should be replaced periodically. The use of a desiccant when drying seeds greatly improves their stability.
Keep cool, keep dark, and keep dry! Maintaining a constant environment with little or no fluctuation is vital to ensure the stability your stored seeds.
The jury is still out on the best location for optimum storage results—each having pros and cons; here are the most common recommendations: