How to store cannabis seeds correctly

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Cannabis seeds, like all living organisms will go bad if they are not stored correctly. Poor storage could cause them to go moldy, dry out even germinate if they become moist. Storing cannabis seeds isn’t difficult and there is no reason why correctly stored seeds won’t stay viable for years to come.

There are three key things you need to remember; Keep them in cool, avoid light and heat exposure and keep them dry. Get this right and you can pretty much guarantee their freshness and viability.

To learn how to store cannabis seeds and keep them fresh in a freezer, refrigerator or a closet, read on…..

Where can you store cannabis seeds to keep them fresh?

Cannabis seeds can be stored in a number of ways providing they are kept cool, dark and dry. Lots of growers use refrigerators or a freezer. But while seeds can be kept for longer periods in cold temperatures they also have a much greater chance of becoming moist which could cause them to go bad.

How to store cannabis seeds in a refrigerator

Fridges are great places to store cannabis seeds to keep them fresh for long periods. However anywhere that moisture is present poses a risk for cannabis seeds. If cannabis seeds come into contact with moisture, it could cause them to germinate or go moldy. Most refrigerators by design contain moisture. Just wipe your hand along the back wall of yours inside and you will most likely feel little beads of water. Moisture in refrigerators builds up because of the constant temperature fluctuations. The main cause of this is the fridge door being opened and closed throughout the day or through a poorly made door seal that does not keep the inside airtight.

If you decide to store your cannabis seeds in refrigerator use a good quality, dry one that has a visible thermometer and just remember, the less you open that door the better. You should also keep your seeds in a darkened airtight glass jar with some silica gel sachets so that should any moisture build up in the fridge your seeds will be kept safe and dry.

Another thing to consider is that if you store the cannabis seed in the refrigerator, it’s very important to let them come back to room temperature before germinating them, as sudden temperature changes can cause damage to the seed and make it impossible for it to pop.

  • The ideal temperature for storage is 4ºC.
  • Use a good quality dry refrigerator.
  • Store seeds inside a glass container.
  • Place a silica gel sachet inside the container.
  • Leave seeds at room temperature for 24 hours before attempting to germinate them.
  • Keeps seeds fresh for at least 2 years.

How to store cannabis seeds in a freezer

With anything organic, the lower the temperature, the slower it degrades. The same rule applies to cannabis seeds, which means if you are storing them for very long periods of time freezers work great. However, freezing seeds does come with its risks.

Most freezers are not moisture free so you need to be even more careful with how they are stored and make sure the container they are in is 100% air tight.

One of the major risks that comes with freezing cannabis seeds is damaging them during the process. Normal freezer temperatures are around -15 to -20ºC, this freezes the seed and the embryo inside it which becomes brittle. If the seeds are shaken or handled roughly it could cause the embryo to break. It is also very important that seeds are defrosted slowly by placing them inside a refrigerator first to bring their temperature gradually up before being introduced to room temperature, once they have been room temperature for 24 hours they can be germinated.

For the average home grower it is not necessary to store cannabis seeds in a freezer, a fridge will do just fine and should keep seeds fresh for 2-5 years.

  • Seeds should be frozen at -15 to -20ºC.
  • Keep them inside a glass airtight container.
  • Handle with care and defrost slowly.
  • Keeps seeds fresh for 2-5 years.
  • Not necessary unless you need to keep seeds fresh for longer than 2 years.

How to store cannabis seeds in a cupboard or closet

Regardless of where you choose to store your cannabis seeds you should keep them in a sealed container, such as an airtight jar or bag, this will help to protect them from moisture and light. Ideally they should then be stored inside a cupboard, or cabinet that is in a cool part of your house. You should avoid storing cannabis seeds anywhere where there could be big temperature fluctuations such as near a radiator or draft window.

Cannabis seeds aren’t cheap and saving leftover seeds and correctly storing them will keep them viable for several years saving you plenty of money and providing a nice supply of seeds for future grows.

What are the best storage containers for cannabis seeds

Seeds are best kept inside glass containers. Plastic and other materials can bend and deform in warm or cold environments whereas glass will keep its form. So whether you are storing your seeds in a fridge, freezer or cupboard, glass containers with a rubber seal such as mason jars are the best.

To give your seeds another layer of protection and to keep them organized, use plastic zip lock bags as well. And if you are storing various different strains, remember to label them first. Then to guarantee their freshness, place a couple of silica gel sachets into the glass jar with the seeds.

Overall, it’s important to store the seeds in a controlled environment, with a consistent temperature and humidity level, in an airtight container away from light, and in a cool, dark place such as a refrigerator or a freezer but for shorter periods a cupboard will also do.

How long can cannabis seeds be stored?

The truth is we don’t actually know the maximum length of time that a cannabis seed can be store for. What we do know is that they can be stored for several years, even decades and possibly centuries if kept in optimal conditions. The shelf life of cannabis seeds varies depending on the storage conditions and how old the seed is upon storage.

Freezer – Seeds kept in a freezer should last 5+ years but could theoretically last decades.

Refrigerator – Seeds kept in a refrigerator should last 2-5 years.

Closet – Seeds kept in a cool, dark closet should last 1-2 years.

It’s important to note that as the seed gets older the germination rates will decrease as well as the rate of seedling failure. So even if the seeds are stored correctly for several years expect some to not germinate.

It’s also important to note that seed viability can also be affected by the initial quality of the seed, genetics, and the seed’s exposure to environmental factors such as temperature, humidity, light, and other conditions prior to storage.

Will old cannabis seeds still germinate?

If you have followed the advice given above and stored your cannabis seeds correctly then you greatly improve your chances of successful germination. However, the ability of old cannabis seeds to germinate varies depending on a number of factors, such as the storage conditions, age of the seed and how quickly after being produced it was stored correctly. Generally speaking, cannabis seeds can be stored for several years if kept in ideal conditions they will still have the potential to germinate. However, the germination rate of older seeds may be lower than that of fresh seeds.

cannabis seeds germinating after being stored

What to avoid when storing cannabis seeds

When storing cannabis seeds, there are several things to avoid to ensure the seeds maintain their viability and have the best chance of germinating when ready to use. Some things to avoid include:

Exposure to light: Light can cause the seeds to dry out and lose their viability, so it’s important to store the seeds in a dark place or in an airtight container that blocks out light.

Exposure to moisture: Moisture can cause the seeds to become moldy or rot, so it’s important to store the seeds in a dry place or in an airtight container to protect them from moisture.

Exposure to extreme temperatures: Extreme temperatures can cause the seeds to lose their ability to germinate, so it’s important to store the seeds in a place with a consistent temperature and to avoid exposing them to temperatures that are too hot or too cold.

Exposure to chemicals or physical stress: The seeds should not be exposed to pesticides, fertilizers, or other harmful chemicals, as well as physical damage from rough handling or exposure to high levels of radiation.

Not keeping track of the storage time: It’s important to keep track of the storage time, to avoid using seeds that are past their shelf life, as the germination rate decrease with the seed’s age.

By avoiding these things, you will ensure that your cannabis seeds maintain their viability and have the best chance of germinating when ready to use.


Joe Musgrave

Joe Musgrave is a keen 420 blogger who writes about all things cannabis. After harnessing his green thumbed skills through years of working on cannabis farms, Joe now shares his knowledge with the rest of the online 420 community.

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