How to Properly Store and Preserve Cannabis Seeds [Explained]
If you don’t begin with great seeds, you can forget about producing a harvest of high-quality marijuana. A lot of growers seem to forget one simple fact: Your seeds are alive! Although cannabis seeds are fairly durable, improper storage can ruin them. If you’re paying $10-$20 a seed, losing a full batch is an expensive mistake.
Before your marijuana seeds germinate, they are in a similar state to animals when they hibernate. Like all living organisms, your seeds can die if you don’t take care of them correctly. The good news is that cannabis seeds can last for five years after harvest with proper storage.
In this guide, we outline how to store and preserve your cannabis seeds. We focus on the following:
- Insects & Pests
- Germinating old seeds
Keeping Light Away from Your Marijuana Seeds
You must keep your seeds in a location that is cool, dark, and dry. It is best if you keep the seeds in their original packaging. When they are exposed to temperature changes or light, cannabis seeds begin using their store of nutrients. This is a disaster because they ultimately won’t have the nutrients to germinate.
When they are exposed to temperature changes or light, cannabis seeds begin using their store of nutrients.
Make sure your seeds remain away from light, as it can directly trigger germination.
What’s the Right Storage Temperature?
The best temperature to store your cannabis seeds at is between 43- and 47-degrees Fahrenheit. The lower the temperature, the less likely your seed is to germinate unexpectedly. Experienced growers tend to have special refrigerators to store their seeds. Ideally, your fridge is a no-frost model. If you can place the seeds in the fruit and vegetable section, that is even better.
Another option is to freeze the cannabis seeds. If you go down this route, please ensure that you vacuum pack them first. Then put them in a dark container. Also, it would help if you germinated these seeds immediately once they come out of the freezer. Don’t allow them to thaw first.
What About Humidity?
Here is a quick overview of what will likely happen to cannabis seeds at different humidity levels:
- <8%: The seeds will attract insects and other pests.
- 9 – 20%: Your seeds are more likely to develop fungi inside and out. They begin sweating at below 20% humidity. However, 8-10% is a ‘sweet spot’ for long-term storage in the right conditions.
- 21 – 30%: The ideal humidity level for cannabis seed storage.
- 31 – 60%: This is the germination zone, particularly once the humidity level goes past 40%.
- 61%+: You are endangering your seeds the higher the humidity level goes. Once it reaches 80%, your seeds will wilt and die in approximately 12 hours.
Your cannabis seeds need a certain level of moisture for germination. If the humidity level gets too high, your seeds will rot in storage. An extremely low level of humidity of around 8-10% is suitable only for long-term storage. If it drops below 8%, you offer any insects present in the seeds the chance to become active and start reproducing.
The Right Storage Options for Your Cannabis Seeds
You now understand that you must store the seeds away from direct light. We have also outlined the need for relatively low humidity and a refrigerator-level temperature. Different options are available depending on how long you intend to store the seeds.
If you only require short-term storage, a dark drawer or cupboard is sufficient. The most important thing, regardless of the duration of storage, is to avoid temperature and humidity fluctuations. Rapid variations in temperature, in particular, can destroy your seeds. If you live in a location with warm daytime temperatures and cold nights, avoid outside storage.
For short-term storage, place the seeds in a container with desiccant. Seal it, and place it in a cool, dark place.
Once you enter medium-term storage (a few months), it is time to use an airtight container. Examples include a mason jar or Ziploc bag. Place this sealed container in the fridge. Remember that opening your fridge can cause significant temperature fluctuations. As a result, it is ideal if you have a second fridge that is seldom used.
Also, you should note that modern fridges have low humidity levels. If the humidity is too low, your seeds will begin using up nutrients.
If you want to store your seeds for at least six months, use a vacuum-sealed container. You can achieve this effect by removing all the air from a Ziploc bag. There are also special vacuum-sealed containers available online. Put the sealed bag in a dark container and put it in the fridge.
You also have the option of placing the seeds in the freezer. Remember, though; you need to germinate them immediately upon removal.
A Note on Insects & Pests
Imagine paying $100+ for seeds, going to the trouble of storing them, only to find that insects ruin them. Unfortunately, all you need is one insect in a container to destroy all of your seeds. The first consideration is to avoid exposure to ultra-low humidity. However, for long-term storage, this is precisely what you are supposed to do!
One option is to spread diatomaceous earth (D.E) where you store them. This is a type of sand that has a fossilized algae base. Crucially, for our purposes, it serves as an excellent natural insecticide. Unfortunately, you shouldn’t use D.E if you plan to store your seeds in a fridge with other food.
Imagine paying $100+ for seeds, going to the trouble of storing them, only to find that insects ruin them.
It would help if you also stored your seeds as high above the ground as possible. This reduces the possibility of a pest like a rodent coming in and feasting on the seeds.
Insects and pests also thrive in dirty storage areas. As a result, you must ensure the storage area remains clean. Otherwise, you won’t just attract pests to your seeds; microbes will form and damage the seeds. Do you want to consume marijuana from contaminated seeds?
You can ‘test’ your seeds once you have removed them from storage. Place them in water. If they sink, they should be fine. However, if they float, it is more likely that they are bad seeds. You can still try to germinate, but there is a greater risk of producing poor-quality cannabis, or else the seeds fail to sprout. You can keep floaters in water for approximately 72 hours to see if they sprout a tail.
If you have old seeds not stored in ideal conditions, there are still a few ways to germinate them.
- Remove the hard ridge with a sharp knife.
- Soak the seeds in carbonated water with germination booster, fulvic acid, or hydrogen peroxide. Use room temperature water, and perform this pre-soak for at least 12 hours in a dark area.
- Scratch the tough outer shell with sandpaper. Believe it or not, this process could help warmth and moisture get inside. This process is called ‘scarring’ and should happen before you soak the seeds.
- Make a small cut into the shell as a last-ditch attempt to get it to sprout.
Final Thoughts on Storing and Preserving Cannabis Seeds
If you purchase marijuana seeds and intend to use them almost immediately, you should have no issues. Even so, it is probably best to keep them away from direct light. In the short-term, a dark cupboard is sufficient as long as the temperature and humidity are reasonable.
Once the goal is to store cannabis seeds for months rather than days or weeks, everything changes. You need an airtight container, which you should store in a fridge. Include a vacuum-sealed container if you plan to store the seeds for several months or longer.
When storing cannabis seeds, you must ensure they are not exposed to germination conditions. This means keeping them away from direct light. Also, store in 20-30% humidity (8-10% for long-term storage) and a cool temperature. Keep the environment clean to avoid pests, and consider the tips above for germinating old seeds.
How to Store Marijuana Seeds Properly
T here’s a lot of reasons to store cannabis seeds rather than just planting them in soil and letting them do their work. Sometimes you have some seeds leftover from your new favorite strain and don’t have the space available where you live to plant it. Sometimes you’re buying seeds for later use once you’ve got the time and energy for your planting project. Sometimes you’re just stocking up for an uncertain future.
Whatever the reason, you need to be sure those cannabis seeds stay viable in the long term. Properly stored 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 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 storing your cannabis seeds, especially for the long term.
When it comes to preserving your 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 seed’s 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 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 ℉.
It’s very important that this temperature remains stable for the long term. If you are refrigerating your 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 seeds over time. While it’s up for debate whether freezing 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.
Humidity is another enemy in your battle for long-term storage because any hint of moisture is another clue to the seed that it’s time to stretch its leafy arms and legs. If the seed shell breaches before it’s in the soil, rot can set in.
However, you don’t want your 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.
Besides being dark, you want to expose your seeds to as little oxygen and carbon dioxide as possible. These gases are what growing plants breathe, as well as the pests that consume them. If you’re refrigerating your seeds, make your container as airtight as possible. If you have some vacuum-sealed plastic on hand, even better.
Much like heat and humidity, light tells that 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 seeds in a dark or opaque container. Without exposure to light, they’ll keep dozing long term.
Some cannabis 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 seeds to remain viable, so be sure to do some research beforehand.
Storage Methods for Cannabis 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 cannabis seed storage methods.
If you’re storing your 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 seeds should also stay dormant in the short term. Plus, an envelope makes it easy to Sharpie the name of the 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 seeds.
Unlike a mailing envelope, glass jars are airtight which makes them much more suitable for long-term cannabis seed storage. 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 seeds long term, you should also throw in a desiccant pack to keep the humidity stable.
Be sure to separate the pack from the 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. 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 seeds long term, vacuum sealing your seeds in thick Mylar bags can keep your seeds viable for up to half a decade. Since the bags are designed for long term storage, they’ll work well for your seeds as long as you make sure they were stored at the right humidity (a desiccant pack helps with this) and away from the light. This is one of the best options if you’re refrigerating your seeds.
Seeds of Wisdom
In conclusion, cannabis seeds can be stored for the long haul and 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 seeds will last. However, when it comes to planting seeds with the most chance of success, sooner is always better.
What are your best methods for storing seeds? Share in the comments below!
How To Store Marijuana Seeds So They Last For Many Years
Incorrect storage can cause any number of issues all of which have the same result: your seeds will no longer germinate.
But if you store them in the proper environment and you keep that environment constant, you can preserve your weed seeds for 5 years or more.
Let’s find out exactly what you need to do to store marijuana seeds the right way and ensure you can still germinate them successfully several years down the road.
How To Store Marijuana Seeds
We often get asked: “Do marijuana seeds go bad?” And the answer is, yes, just like any other type of seed. But if you care for them properly, they can last many years. And that’s exactly what we’ll help you do.
First we’ll cover the ideal condition for seeds, so that you can maximize their shelf life. Then we will cover all of the best containers and locations for actually storing seeds. We’ll also mention a few common ones that are less than ideal.
Ideal Conditions For Storing Weed Seeds
To keep your seeds viable as long as possible, you need to store them in a cool, dark and dry location. The most important thing to avoid are fluctuations in the environment. You want to keep it as steady as possible. Here are the exact conditions you want to provide.
Seeds must be stored in the dark, because light triggers germination. If seeds are exposed to light, even if they do not have any of the other conditions required for germination, the chemical processes for germination are triggered.
This means they begin using up their stored nutrients, which reduces their germination power. When you then try to germinate them later, they may not have sufficient nutrients left and the chances of success are much lower.
Correct humidity levels are vital. If the environment is too humid, weed seeds absorb moisture from the air. This can trigger germination or cause other issues like rotting.
If you are only storing your seeds for a short period of time (no more than a few months) a relative humidity between 20% and 30% is fine. If you are storing them longer, you’ll want to go lower than that. Aim for a humidity level of around 8% to 10%. Even for short time periods, drier is better.
A good way to ensure the seeds stay dry is to include a desiccant in the container in which you are storing the seeds. A common desiccant are those little packets of silica gel that are often included with products that need to stay dry. Include one in the container with the seeds and swap it out every 6 months. You could also use rice kernels in a pinch.
The cooler the better, when it comes to storing cannabis seeds. but only up to a point. You do not want the seeds to freeze, since that can damage them, unless you have the equipment to freeze them rapidly.
The ideal temperature is between 42° and 46° F, which is approximately 6° and 8° C. You can certainly store them in warmer temperatures, but it will reduce the shelf life. If you plan on keeping them for a long time without germinating them, you’ll want to keep them cool.
If a seed gets a steady supply of fresh oxygen, respiration can occur. This may lead to premature germination. To prevent this, store seeds in an airtight container. Inside a vacuum is ideal, but just somewhere that is sealed off is sufficient.
Maintain Fixed Conditions
As mentioned, it is very important to maintain steady environmental conditions. Fluctuations in temperature, humidity, light levels or oxygen levels all reduce the shelf life of your seeds. Furthermore, exposure to the external environment can also allow pests or harmful microbes to enter and damage the seeds.
Best Containers For Storing Marijuana Seeds
People store their seeds in all kinds of different containers. Since they are small, you can put them in just about anything. But many common containers used to store weed seeds are not great. We’ll begin with the best options and end with some that are not recommended.
If you ordered your seeds from a top online seed bank, they probably arrived in sealed packaging. If you haven’t opened it yet, it is best to just leave them sealed in that package.
Whichever type of container you choose, it is best if you can vacuum seal it, or vacuum seal the seeds inside a smaller container within the other one. As mentioned above, keeping oxygen levels low is ideal and the best way to do that, and also ensure minimal environmental fluctuations, is to keep the seeds in a vacuum.
If you plan on storing a lot of seeds, it might be worth investing in a vacuum sealer. Then you can vacuum seal them inside a small container and place that inside a larger one like a glass jar.
Glass jars, like mason jars, are ideal for storing seeds. Their one drawback is that most are not opaque, so you’ll have to keep them in a dark location or cover them with something, so that the seeds remain in the dark.
Ideally, you want to use a glass container with a glass lid. The lid must seal, of course. You want a glass lid, because a lid made from a different material will react differently from the glass to changes in the external environment. This could result in the lid contracting or expanding relative to the glass and weakening the seal.
Plastic Container (Like A Film Canister)
Plastic is not the best material for storing weed seeds, because it has microscopic pores that let in some of the outside environment. They work fine for shorter term storage, but if you are planning on keeping your seeds in storage for a longer period of time, you should avoid plastic.
Plastic Bags (Like Ziplocs)
Plastic bags can work in a pinch, but they are far from ideal. Most are not airtight, which means they can not prevent fluctuations in light, temperature and humidity.
You can use them for short term storage, but you’ll want to find something better for a longer term solution. A vacuum sealed plastic bag that you put inside a glass jar is a great solution, however.
Paper envelopes are great for holding seeds, because they generally keep out light. But they are not good on their own. If you put your seeds in a paper container, you need to place that within a better container, like a mason jar. This is a good way to add some light protection to a transparent glass jar.
Best Places To Store Cannabis Seeds
The following are all good places to store your weed seeds, if you want to ensure they stay viable as long as possible. We’ll begin with the ideal storage space and end with some locations that are less than ideal, but can work in a pinch, for shorter term storage.
Seeds are best stored in a cool, dry, dark location. That basically describes a fridge. With one caveat. You can’t open the door all the time.
That is why it is best if you have a refrigerator specifically dedicated to the storage of seeds. Or at least a second fridge that rarely gets opened.
You regular fridge gets opened constantly throughout the day. Every time you open it, the inside sees fairly large temperature fluctuations. The humidity level changes as well.
If you have no other option, at least put the seeds in the back of the fridge, where they are least affected by changes in temperature from the opening door. If there is a desiccant in the container with the seeds, the changes in moisture won’t affect the seeds either.
If you don’t have a fridge that would work, you could also store your seeds in a cool basement. The main thing to look out for here is that you protect them as much as possible from temperature and humidity fluctuations. You can use some type of insulation the maintain a steady temperature and desiccants to maintain a steady humidity level.
You could also bury your seeds underground. This may seem strange, but if you go down deep enough that changes in air temperature don’t affect the ground temperature, this is actually a great storage location. You’ll definitely want to use desiccants to keep the humidity steady. And, of course, make sure you remember where exactly you buried them.
A regular room in your house can work just fine for storing seeds, too. But it’s more of a short-term solution, since the temperature is likely to be higher than is ideal. You can again use desiccants to keep the relative humidity low.
Common spots are in a closet, a cupboard, or a drawer. Naturally, you want to ensure the seeds are kept in darkness and not disturbed. Stored like this, seeds can still last a fairly long time: even as much as a few years.
Just make sure to protect them from temperature fluctuations. Even if temps are warmer than is ideal, they will be ok, as long as the temperature remains constant.
How Long Can You Store Cannabis Seeds?
If you provide the perfect conditions, marijuana seeds can be stored for up to 5 years and still be viable. If you give them decent conditions and maintain those conditions (i.e. no major fluctuations in the environmental conditions), you can expect the seeds to still be good after a year or two.
Naturally, the longer you store them, the lower the chances of successful germination. Storing them improperly also reduces the rate of germination. So store them well and use them as quickly as you can, in order to ensure the highest possible rate of germination.
Tips For Storing Marijuana Seeds
The following are some general tips that will help you out when storing your marijuana seeds.
It is always a good idea to label your seeds, especially if you are storing a number of different ones. But even if you are only storing a few seeds and they are all the same strain, we still recommend you label them. You may not remember what they even are a year from now. And if there are others in the house, it’s a good way to let them know not to disturb the seeds.
Use Desiccant Correctly
When putting desiccant in the container with the seeds, it is best to keep the two separate. You can create a boundary between the weed seeds and the desiccant by using wool or cotton.
Before you seal your container up tightly, make sure to check it carefully for pests. You do not want a single insect in the jar with your seeds, because it could potentially do serious damage to them. Once you’ve confirmed the container is pest free, seal it up tightly to ensure it stays that way.
Storing Weed Seeds: Final Thoughts
In order to keep your seeds viable as long as possible, you want to make sure you store them in an environment that is cool, dry and dark. You also want to make sure the container you store them in is sealed tight, because the most important factor in making sure your seeds last is a consistent environment. Fluctuations in light, temperature and humidity do serious harm and will likely render your seeds useless.
A glass jar is an ideal container, but your seeds may also already be in a great container. If you bought them online and had the seeds sent in the mail, chances are they are already sealed up tightly. Unless you need to open the container with the seeds, you can just leave them in there.
The bottom line is you paid a lot of money to buy your seeds. Make sure you store them properly, so you don’t end up ruining them and losing the investment you made in them.