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.
How to dry and store cannabis seeds
Seeds air-dried during humid weather require additional drying with desiccants such as silica gel before final storage (but don’t use heat!). Most seeds benefit from drying with silica gel if they are to be stored for very long. The longest storage life for desiccation-tolerant seeds is achieved by drying them to between 5% and 7% moisture content (by weight) and then storing them at several degrees below freezing. As storage temperature rises above freezing or moisture content rises above 5 to 7%, longevity in storage goes down and the incidence of mutation rises. Seeds dried to a low moisture content with silica gel and then stored in a freezer can usually retain viability for many years.
To use silica gels for drying seeds, place equal weights of dry silica gel and seeds to be dried in a well-sealed jar for 7 to 8 days. Then transfer the dried seeds quickly into airtight storage jars and place in a freezer, refrigerator or other cool, dark place.
Since desiccation-tolerant seeds stop almost all metabolic activity as they mature and dry, they can be stored for months or even years with only minor loss of viability and vigor. Desiccation-tolerant seeds which show high germination percentages when fresh—if properly dried and stored in a freezer—can typically retain their viability for years.
Seeds with low initial germination rates will begin to lose viability fairly quickly, however, even under ideal storage conditions. Seed lots with a low initial germination rate should be regrown as soon as possible. If a batch of seeds with poor germination is grown out and a healthy batch with good germination produced from them, the healthy batch can then be dried, frozen and stored for long periods successfully.
Avoiding Problems With Stored Seeds
Mold and Mildew: A common problem with stored seeds is mold or mildew resulting from incomplete drying before storage. Dry your seeds thoroughly before storing them (though drying them to 0% moisture will of course cause their death). If seeds sweat on insides of jars during storage, they are too wet and must be dried further in order to store successfully. At this point the use of a desiccant is a good idea. Don’t tarry, because damp seeds will mildew quickly.
Temperature and Moisture Fluctuations: Fluctuation in temperature or moisture levels of stored seeds lowers the seeds’ longevity significantly, causing loss of viability and vigor or even seed death. Rapid moisture fluctuations are particularly damaging to seeds. High moisture or temperatures encourage mutation of seed tissues—especially in root tips, which remain more active than other seed tissues. Cellular mutations affecting metabolism or root tissue structure are a common cause of seed failure upon germination. Dry your seeds properly before placing them in cold storage. Keep your stored seeds at a constant temperature if possible and remove them from storage as seldom and as few times as possible. When seeds are removed from cold storage in order to retrieve samples, allow the entire container to come slowly to room temperature before opening the seal. This will help prevent condensation of atmospheric moisture onto the cold seeds which might otherwise occur.