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If you grow only a few plants at a time in your indoor or outdoor garden, you probably have cannabis seeds left over with every purchase. In order to ensure these extra seeds remain viable until you’re ready to plant them, it is important to preserve them in the correct container and conditions.
If your seeds are properly cared for, you should find they remain viable for as long as three years.
Best Conditions for Storing Cannabis Seeds?
A cool, dry, and dark location is the ideal place to preserve your Growers Choice cannabis seeds. Increased temperature and humidity and the presence of direct light will trigger the dormant nutrients in the seeds, using up those essentials before your seeds ever see water or soil. Maintaining low temperature and humidity levels and eliminating light are vital to longevity.
- The humidity in your seeds’ storage area should be between 6% and 9%, unless you have left the seeds unopened, in their original medical-grade glass packaging, in which case humidity should not be a factor. If the seeds are unpacked before they are preserved, however (if, say, you remove a seed to plant it and are saving the others), humidity levels above 12% may the development of fungi on your cannabis seeds. Essentially, the higher the humidity, the shorter the seeds’ lifespan.
- Though temperature should be kept stable, quite a range of temperatures will ensure the preservation of your cannabis seeds. The cold environment of a fridge or freezer will slow the life process, along with the rate of degradation. To preserve seeds for a short time, even a dark cupboard – in an area with little temperature fluctuation – is suitable. If you have a second fridge or freezer that is opened more rarely than the one in your kitchen, this is also ideal for long-term storage; even opening your fridge for only a few seconds multiple times a day can cause potentially damaging temperature fluctuations (though it is still preferable to a warm countertop).
Preparation for Preserving Cannabis Seeds
Though ideal conditions are more pertinent to long-term preservation, it is best to store all your cannabis seeds with the assumption they will be preserved for years. This better ensures your seeds will be viable whenever they’re used.
The container in which you preserve your marijuana seeds must be airtight, or vacuum sealed. Black film canisters are a suitable choice for short term, as they are completely lightproof and have a good seal. To preserve over a long period of time, however, glass or metal is preferable. The porous nature of plastic allows moisture to enter eventually, making humidity impossible to control. Any glass or metal containers should also have glass or metal lids.
Modern refrigerators are usually very dry environments, and this makes air tightness even more vital for preserved cannabis seeds. If any air can pass in or out of the container, it will be leeched out of the seeds over time, resulting in a detrimentally low humidity level.
Weed Seeds Inside the Storage Container
If the weed seeds you plan to preserve are no longer in the well-sealed package they came in, place them in a paper envelope before putting them into the container. Paper allows any moisture trapped in the cannabis seeds to escape; dedicated “seed savers” or seed envelopes can be purchased at any garden center.
To help absorb excess moisture that may make its way into your container while the cannabis seeds are preserved, add a bit of rice or silica (or silica-based desiccant sachels, the kind you find in your new shoebox) to the container as well. Add a weight of desiccant equal to the weight of the seeds. If you have the proper equipment, you can also vacuum-seal the containers before putting them into the fridge.
The Best Cannabis Seeds to Preserve
In general, the heartier the cannabis strain, the longer those preserved seeds will remain viable. Regardless of their lineage, however, always check each seed for cracks before storing. Seeds with surface damage will have reduced longevity, and should be planted within the first few weeks.
Seeds must be completely dry before they are preserved, lest the moisture remaining in them leak out and speed up their decay or, in the worst case, cause rotting or molding. At Growers Choice Cannabis Seeds, we ensure all our seeds are thoroughly dried, but if you wish to test them, there is a simple method to do so.
Place your cannabis seeds in a container on the counter for a few hours. If condensation develops inside the container, the seeds are too moist and should be dried further before being preserved. This can be done by combining them with silica, which is how most distributors dry them in the first place.
Then put your well-dried, viable seeds in their envelope and container. Then label the container with the strain, the number of cannabis seeds, and the date they were preserved. If you plan to store them for a very long time, consider placing this label inside the container so it does not fade or fall off.
Our Most Resilient Cannabis Seed Strains:
How Do I Preserve Cannabis Seeds?
A dark cupboard in a relatively cool location should be just fine to preserve your cannabis seeds for as long as three years. The biggest potential problem with this storage method is the inevitable fluctuation in temperature between different seasons and even different times of day. Your fridge temperature is probably more stable.
Once your preserved seeds have reached the temperature you want – whether in the fridge, freezer, or cupboard – keep them at this temperature until you plan to germinate them, if at all possible. As stated before, fluctuations in temperature can activate the germination stage and ruin viable seeds.
Keep in mind that however well packaged your seeds, the germination rate will still decrease over time. Cannabis seeds that have been preserved for several years will often take longer to germinate, and it is always possible some will not develop roots at all. If you plan to plant only a few seeds at a time, we recommend buying a smaller package of cannabis seeds. Though the cost per seed will be a bit higher, the higher number of viable seeds is likely to save you money in the end.
Can I Put My Pot Seeds in the Freezer?
Though some growers seem content to store their pot seeds in the freezer, this may not be as suitable a location as the refrigerator. Freezing seeds can rupture the cells within – especially if there is any excess moisture. If you store your cannabis seeds in the freezer, be prepared for some of them to be nonviable when they’re removed.
When you want to use your preserved cannabis seeds, remove them from the fridge, but leave them in their container until they have acclimatized to room temperature. This will force condensation to develop on the container instead of on the seeds themselves. Then you’re ready to move on to Germination!