Vacuum sealing cannabis seeds

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.

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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.

Glass Jars

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.

Mylar Bags

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!

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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Frequently Asked Questions About Cannabis Seeds

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,, 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.

Storage Methods

The jury is still out on the best location for optimum storage results—each having pros and cons; here are the most common recommendations:

Is it Bad Practice to Vacuum Seal Weed? [EXPLAINED!]

It is always a good feeling to ‘find’ cannabis nugs we had completely forgotten about. It saves you a few bucks and a trip to your nearest dispensary. However, is it safe to use weed you discover after a few weeks or months? The answer depends on how the marijuana was stored. If it has been left exposed to heat or sunlight, its THCA will be converted into CBNA, which is then converted to CBN when heated.

As a result, you won’t enjoy the same psychoactive high and may even feel a little dizzy or nauseous. On the other hand, cannabis with a lot of CBN is still potentially useful as a topical. If, on the other hand, your marijuana has been stored in an airtight container in a place shielded from sunlight it could be ‘good’ for up to two years according to most experts.

There are several popular methods of storing cannabis and vacuum sealing is the subject of much controversy. Some users claim it is a fantastic method of keeping bud fresh for a long time, while others suggest it will ruin your weed. What is the truth?

What is Vacuum Sealing?

It is a method of packaging popular in the food industry and involves removing air from the package before you seal it. You can place the items in a plastic film package to remove air from the outside, and shrink film can be used in a pinch. The goal is to remove oxygen from the container to extend the shelf life of products.

It makes perfect sense to vacuum seal marijuana because the process reduces atmospheric oxygen and also prevents the evaporation of volatile compounds. Moreover, vacuum sealing also inhibits the growth of bacteria that would otherwise ruin your marijuana. Once you place your vacuum sealed weed in storage away from sunlight, it should theoretically be usable for years.

There are a variety of machines on the market that do the hard work for you. It is also possible to create your own vacuum sealed product using a Ziploc bag and water. Place the item in the bag and seal it but leave an inch of the seal open. Lower the bag into a tub of water, and be amazed as water pressure pushes the remaining air out of the bag. Seal off the opening before the bag becomes submerged and pull the bag out of the tub.

Is it a Good Idea to Vacuum Seal Cannabis?

On the face of it, there is no reason NOT to vacuum seal cannabis. The main thing is to ensure that the material you use does not contain harmful chemicals. For example, some plastics contain BPA (bisphenol A) which is an industrial chemical that seeps into the material and can imitate the body’s hormones and hurt several bodily functions.

It is better to vacuum seal marijuana than keep it in plastic baggies. These containers do little to prevent air, light, heat, cold or moisture from coming out of the herb. Even sealable baggies are not effective storage options in the long-term. Perhaps the biggest issue with vacuum sealing is the use of plastic. Plastic has a static charge that pulls trichomes from your plant matter onto the material.

It is common for marijuana users to vacuum seal their weed and then freeze it. The process of vacuum sealing eliminates issues with moisture, but you could end up crushing your buds. Freezing can also cause the trichomes to become brittle and break off when handled. Therefore, if you elect to freeze your weed, you have to be incredibly careful when taking it out.

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There are usually two types of vacuum seal bags people use. The first option is a food-preserving bag which could allow you to seal up to 1,000 grams of weed depending on the size of the bag. These containers remove all of the air, a huge factor in reducing the risk of mold. The process of compression may reduce the quality of the bud, but at least you keep the aroma and flavor intact. When properly cured, dried, and vacuum sealed, marijuana could last for several years.

The second type of vacuum seal bag is the type that stores clothes. A vacuum cleaner is used to extract the air, and these thick bags have a zip seal that is airtight. You attach the vacuum cleaner to the bag’s nozzle to suck out the air and keep the buds nice and fresh. These bags are the right choice for those who grow marijuana on an industrial scale.

Storing Marijuana – Best Practices

No matter how you store your weed, keep the following factors in mind because they dictate how fresh your cannabis remains.


This process involves heating raw cannabis to activate its cannabinoids. It automatically happens when you smoke a joint or vaporize the herb. If you need to make edibles, you have to place the raw cannabis in the oven to ‘decarb’ it. When your weed is exposed to sunlight, its psychoactive THC degrades into CBN. The result is marijuana that provides a more sedative high.

Air Temperature

The temperature your weed is exposed to makes a BIG difference to its quality. It is important to note that common molds and mildew thrive in temperatures of between 77- and 86-degrees Fahrenheit on weed and other organic matter. If you store your cannabis at a temperature higher than 86 degrees, you will dry out the terpenes and cannabinoids.

Terpene molecules vary in size with the smaller ones evaporating at temperatures in the high 60s Fahrenheit. On the other hand, excessively low temperatures could damage your trichomes and slow down the decarboxylating process where THCA is turned into THC. While you could store your marijuana at a temperature of between 32 and 68 degrees, in theory, it is best to keep it between 60 and 65 degrees in practice if at all possible.


This is one of the single most important storage considerations. If the humidity is too high, there is an increased chance of mold growth. If it is too low, the trichomes can break off, and the essential oils dry out. Ideally, your weed will be stored at a relative humidity (RH) of between 59% and 64%, with 62% often classified as the ‘sweet spot.’


The sun’s ultraviolet (UV) rays can damage your buds and interfere with how marijuana affects you. Research has revealed that light exposure is the biggest factor in cannabinoids’ long-term stability rate. The study was admittedly conducted in the 1970s but looked at nine samples of weed left out in different conditions for two years. It found that weed retained its best condition in well-closed containers that were well-filled and left in a dark place at room temperature.

How Should I Store My Marijuana?

In the good old days, it was common to store weed in a ceramic pot or a tin can. Vacuum sealing works just fine as long as the material used does not contain any harmful chemicals. Avoid plastic if possible because it can damage the trichomes. When performed correctly, vacuum sealing prevents airborne damage of your nugs, removes oxygen from the equation and can also stop over-exposure to humidity.

You could vacuum seal individual doses and place them in an airtight glass jar. Perhaps the best method of storing weed IS the glass mason jar. It doesn’t allow oxygen in when tightly sealed, is not impacted by residual humidity and prevents your weed from being damaged due to temperature fluctuations. Glass is a great storage material because it doesn’t secrete any unwanted chemical compounds that could interfere with the aroma and flavor of the weed.

If you can, purchase a dark, tinted, or opaque jar to stop sunlight from causing damage to the cannabis. If you can’t find a glass mason jar for some reason, an airtight titanium container is another solid choice. No matter what option you choose, make sure the container is stored in a cool, dry, dark place which could be a cupboard or a drawer in your home; and keep it out of reach of children!

Final Thoughts on Storing Marijuana

In answer to the title question: It is NOT necessarily bad to vacuum seal weed. It keeps your cannabis fresh for years, but it is important not to use plastic if at all possible. Here is an overview of good and bad storage practices: