How to Store Cannabis Seeds (Short & Long-Term)

Cannabis seeds, like all living things, have a window of viability whereafter germination can become challenging, or even impossible. Most cannabis seeds can be stored for between 2 to 3 years from their harvest date in a cupboard, or more than 5 years in a fridge or freezer, before germination rates are lowered.

But it’s not as simple as just throwing your seed pack into the fridge, and doing so without following the proper processes can do more harm than good.

In this article, we’ll look at how to store your cannabis seeds and how long your seeds are likely to remain viable in those conditions.

Stored In The Open (No sealed packaging)

Seed Viability: Around 12 months.

Never store your seeds out in the open. Fluctuations in humidity levels and temperature can wreak havoc on the viability. Additionally, the constant exposure to light can further degrade them over time, leading to low germination rates and modest storage times at best.

Stored In The Open (Sealed packaging)

Seed Viability: 12 to 24 months.

Inside sealed breeder packs, seeds can survive a bit longer in the open. Since they are sealed, they aren’t going to be impacted as much by fluctuations in humidity. Still, temperature variations and exposure to direct light remain a concern. Some packs offer fully dark, sealed storage, while others allow customers to see the seeds through the packaging, which can allow light to directly hit the seeds. Even high ambient lighting can damage seeds over time.

Stored In A Dark Cupboard (Sealed packaging)

Seed Viability: 24 to 36 months

This is the most common method for storing cannabis seeds. It usually involves placing the packs inside of zip locks or sealed containers and then placing them in a dark cupboard. This protects them from humidity swings and light. Temperature is still variable, depending on the room they’re stored in, and the colder the cupboard, the better.

Using this method, you can easily get 24 to 36 months of viability before germination rates start waning.

Stored In A Fridge (Sealed packaging)

Seed Viability: 5 years+

Storing your seeds in the fridge will give you the longest storage time if done right. However, this is also where most problems can occur, as one needs to be meticulous in ensuring no moisture can reach the seeds. Normally, fridges have low humidity, which is ideal for storing seeds. However, during load shedding or power outages, this changes, and as the fridge heats up, more moisture accumulates and can pose a risk to seeds that aren’t very well insulated.

An ideal seed storage fridge is one that is separate from your main fridge. That’s because frequently opening the fridge is less than optimal for long-term seed storage. Using a dedicated bar fridge is ultimately going to give you the best results, but that is one additional cost to factor in.

If you decide to use your main fridge, just be aware of how load shedding may damage the seeds in some cases, and prepare your seeds for the case scenario.

To do this, double-bag your seeds in zip locks, even if they’re sealed with the breeder packaging. Inside those bags, place grains of uncooked rice to absorb small amounts of moisture that may make it through. Do this for both bags you sealed them in. Then place all your seed bags into a plastic airtight container like a Tupperware, along with more uncooked rice for additional protection.

A Note About Storing Seeds in Freezers

While some believe freezing cannabis seeds can extend their shelf life indefinitely, it’s a high-risk method that’s rarely suitable outside of professional seed banks. For freezing to work, seeds must first be carefully dried to a specific moisture level (around 6–9%) and then sealed in airtight, vacuum-packed containers with desiccants. Even the slightest trace of moisture can expand into ice crystals during freezing, damaging the delicate embryo inside the seed and rendering it non-viable. Most household freezers also cycle through temperature changes, causing condensation and thermal stress, two major threats to seed longevity.

Final Thoughts & Considerations

Overall, the best way to store your seeds depends on how long you plan to keep them for. For short-term storage, a cool, dark cupboard is a great option. Once you’ve opened a pack, do your best to reseal it in an appropriate environment. For example, sealing seeds in high humidity is never a good idea. Reseal in low humidity instead.

For long-term storage, a dedicated bar fridge is a great idea. But keep in mind that frequent load shedding, or even just a few long load shedding periods can cause problems.