If you 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?
- Can you germinate cracked marijuana seeds?
- How we store our cannabis seeds?
- How long do marijuana seeds last? let's recap...
How Long do marijuana seeds last after storing them?
Marijuana seeds last 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. Storing seeds is not difficult, you just have to take into account some factors that we explain below. In most cases, a cool, dark, and dry spot is all you need.
Mother Nature’s designed them to respond to their environment with particular heat and moisture to signal the seed when it’s time to germinate. In nature, this 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
A marijuana seed is a living organism which, when correctly stored, remain dormant. All seeds need to germinate is humidity and favorable temperatures.
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 or in a ziplock bag.
Key factors for your storage conditions environment
In order to store your seeds as good as possible, we will discuss the three key factors.
- Humidity level
Moisture is an especially important factor if you are storing 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 airtight container and make sure the seeds are completely dried.
When you buy seeds from us or from another reputable seed bank, your seeds will be delivered in an airtight container. You can then assume that the seeds are already well dried. It is therefore essential to remove only the seeds you need from the packaging and immediately close it again.
If you are uncertain whether your seeds are dry enough, put them in a closed container with a handful of rice or a bag of Silica in it. Leave them in this for a week and then pack them in an airtight container as soon as possible.
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 temperatures can fluctuate wildly, especially during summer. The recommended temperature is at least 5 °C (41 °F) (or lower). 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. The cooler the temperature, the more slowly seed vitality declines.
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.
Just a tip: make 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?
To determine the best place to store your seeds, you can choose from these options:
Cool ✔ Dark ✔ That’s two out of three requirements down. Remember, not properly dried seeds will not last long in the basement either. So again, make sure your seeds are dry when you start storing them!
The best option, I think, is to store them in refrigerators at a temperature between 4 °C and 6 °C (39 °F and 43 °F), and with relative humidity levels between 15% and 20%. And sheltered from light, of course. This spot checks all the boxes.
Another place to keep your stash. The average freezer is about -26 °C (-15 °F) dark and has a minimum of temperature fluctuations 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, but a word of caution though! Some seed banks keep a large stock, so you are at risk that the seeds you purchased were frozen before.. When you freeze seeds that have already been frozen before the chance of killing them is remarkable. For this reason, we do not recommend freezing your seeds, unless you are 100% sure that they haven’t been frozen before.
Where do you keep your seeds in?
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?
A metal box or vault is 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 requiring more care and attention as seedlings.
There are a few tips and tricks to apply in order to increase your chances of successful germination.
Some breeders use sandpaper 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.
Using hydrogen peroxide (H2O2) is another common way to germinate old cannabis seeds (see video below). In fact, this technique can even improve the germination rate.
You need to soak the seeds in a glass of water with a few drops (1%) of hydrogen peroxide, for 24 hours at a temperature of 28 °C (82 °F). The hydrogen peroxide softens the shell and facilitates the water's absorption.
Can you germinate cracked marijuana seeds?
Yes, cracked marijuana seeds can still be germinated as long as the crack does not extend too deeply into the seed.
The seed should still be able to sprout, if it is superficial and does not damage the inner part of the seed where the embryo is located. If the crack is too deep, it will harm the germination ability.
Cracked seeds may be more susceptible to moisture and other environmental factors that could negatively impact their germination rate.
Although it is best to choose a healthy seed that is intact and undamaged (to ensure the best chance of success), a cracked seed still may germinate.
How we store our cannabis seeds?
As soon as we have harvested the fresh seeds, they are dried in a room with an automatic dehumidifier. This process takes about 3 weeks, in which we slowly bring the humidity back to 40%.
After this, we put the seeds in trays containing Silica bags. After about 3 days, the humidity has dropped to 15%, and they are dry enough to be packed. We then pack the seeds in ziplock bags per 5, 10, 20 or 1000 pieces and label them with the name and date. Then they go with several bags in an airtight and light-tight container, and we store them in a refrigerator somewhere in a secret location.
Once a week, we collect the stock for our webshop/ These are also stored in a refrigerator, neatly in alphabetical order, ready to be sent to our customers.
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, in a dark place, 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 your 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 assure 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.
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