Seed Patrol
To store cannabis seeds, keep them in a sealed, light-proof container with a silica gel sachet, inside a fridge running at about 35 to 40 F. The freezer is optional: Royal Queen Seeds calls it usually not necessary, while Mephisto Genetics points to it for storage of a few years.
This is an evergreen how-to; the seed banks’ undated pages are quoted as read.
What the seed banks say, checked against the extension numbers
This desk read the storage pages of Royal Queen Seeds, Mephisto Genetics and Dutch Passion, and Utah State University Extension’s seed storage page, on 23 October 2026. USU writes about vegetable seed, not cannabis.
| Temperature | Humidity advice | Container | Freezer | Longevity claim | |
|---|---|---|---|---|---|
| Royal Queen Seeds | No figure in the text read | Silica gel; No Frost fridge | Sealed, dark | “Usually not necessary” | Up to five years |
| Mephisto Genetics | About 5 C (41 F) | Low, no figure | Sealed | For a few years | Couple of years |
| Dutch Passion | Fridge | “Not necessary to measure” | Sealed, dry, dark | Not quoted | Five years or more |
| USU Extension | 35-40 F | Under 40% RH | Good seal in a fridge | Not covered | Not covered |
How to store cannabis seeds in the fridge without the damp
The one real disagreement is humidity. Dutch Passion says the fridge is an easy way to keep humidity low and that measuring it is unnecessary. USU says the opposite about the appliance: most fridges hold about 40 F but at high relative humidity. Both then land on the same fix, a sealed container. A desiccant soaks up what the seal traps. A second, rarely opened fridge helps; Royal Queen Seeds and Mephisto both suggest one.
See our germination guide and Royal Queen Seeds review.
Frequently asked questions
Can you store cannabis seeds in the fridge?
Yes, and all three seed banks read for this post describe fridge storage, always inside a sealed container. Utah State University Extension warns that most refrigerators sit near 40 F at high relative humidity. A sealed tube or jar, with a silica gel sachet as Royal Queen Seeds suggests, keeps that moisture off the seeds.
Can you store cannabis seeds in the freezer?
You can. Royal Queen Seeds calls freezing usually not necessary. Mephisto Genetics points to the freezer for storage of a few years. For a packet you will open within a few seasons, a sealed container in the fridge is the simpler choice.
How long do cannabis seeds last?
The figures come from the sellers, not from trials. Royal Queen Seeds says seeds kept to its conditions should keep a high germination rate for up to five years. Dutch Passion says fridge-stored seed in a dark, dry container can still germinate well after perhaps five years or more. In the text read, neither page cites a study.
What is the best way to store seeds long term?
Cold, dry, dark and stable. Utah State University Extension, writing about vegetable seed, puts the ideal at 35 to 40 F with relative humidity under 40%, and says never above 70 F or 60% humidity. In practice that means a sealed, light-proof container with a desiccant in a fridge that is rarely opened.
Keep seeds only where home cultivation is lawful for adults, and check your local laws before purchasing or germinating cannabis seeds.