When it comes to storing cannabis seeds, ensuring germination success is all about understanding and maintaining the right conditions.
This guide is designed to empower you with scientifically backed knowledge to store your cannabis seeds confidently, instilling confidence that they’ll be ready to use if days, weeks, or months pass. Seeds are living entities; as a grower, you are responsible for creating the optimal environment for their preservation. I’m here to give you the how-to to make it happen. Let’s dispel any misconceptions and dive into the science of seed storage.
TL/DR
- Moisture is the enemy; for seeds to remain viable, store them in a dry environment.
- Store seeds at a consistently cool temperature, ideally around 45°. Temperature fluctuation can potentially trigger seed growth.
- Store your seeds in a dark place. Light (especially sunlight) can cause your seeds to germinate even if other conditions aren’t met.
- Opt for vacuum-sealed or airtight containers; be sure they can be sealed.
- Always label your seeds with the cultivar and date of storage.
Your Cannabis Seeds Are Alive!
Despite their hard exterior, cannabis seeds are sensitive, living organisms that respond to their environment. Often, people view seeds as non-living objects, but they are the plant’s embryo, which categorizes them as living things. Providing them with optimal conditions is crucial for triggering germination and preserving them in their dormant state.
There is Moisture Inside Your Seeds
Seeds contain a specific amount of moisture. Getting moisture information from seed banks is beneficial but not always provided. However, there are ways to check the viability of your seeds. Understanding the moisture content of your seeds can help you determine the best storage method and tools to accompany your seed packs, such as Boveda packs, orange peels, or other options.
Seed Storage Needs a Stable Environment
Environmental stability is vital. Fluctuations in temperature and humidity are the enemies of seed storage. For instance, fridge doors experience frequent temperature changes, making them less ideal for seed storage than a dedicated cooler that maintains a constant temperature.
What Are the Best Conditions To Store Cannabis Seeds?
The longevity of cannabis seeds depends on how they are stored and their moisture content. You’d think all storage conditions must be the same regardless of timelines, but that isn’t necessarily true. As the time horizon for storing seeds gets longer, the storage conditions will need to be more dialed in to ensure a seed’s integrity.
Here’s a quick guide for how I approach storage for different timelines:
Storing Cannabis Seeds for Weeks
Keep your seeds in a cool, dark, dry place for short-term storage. Avoid exposure to light, heat, and humidity since all these can trigger germination. A drawer or a closet in a cool room can suffice. If you have no tools specifically made for storage, ensure your seeds stay between 50-70 degrees F (10-21 degrees C), their moisture content is at 5% or lower, and the relative environmental humidity is 20-30%. Use airtight containers like mason jars to minimize exposure to air and moisture. Due to a shorter time horizon, you can have slightly more variable conditions, but you still want to ensure they are stable so the seeds aren’t ruined.
Storing Cannabis Seeds for Months
Consider using a refrigerator for a few months of storage. Place the seeds in airtight seed storage containers, possibly with silica gel packs, to absorb any residual moisture.
Cannabis seeds stored for over nine months should maintain a constant seed moisture content of 5% to a max of 7% (or relative environmental humidity of 18-20%) and remain at a constant temperature of -4 F (-20 C). When stored this way, seeds are viable for up to 36 months.
Storing Cannabis Seeds for Years
Freezing marijuana seeds is the most effective method for long-term storage. The best freezer would be one used exclusively for seed storage; that way, there are fewer opportunities to open it and cause temperature fluctuations. An airtight container is a must. Vacuum seal the seeds to prevent moisture ingress. Ensure the seeds are completely dry before freezing to avoid ice crystal formation, which can damage the seed’s viability.
Similar to storage for months at a time, you’ll want to ensure the moisture content of your seeds is between 5-7% or relative humidity of 12-14% and at a consistent temperature of -4 F (-20 C). These seeds will be viable for up to 3 years, though they may last longer; studies have shown the germination rate falls after this period.
What Should You Look Out For When Storing Cannabis?
Based on scientific studies, the optimal conditions for seed storage involve controlling moisture, temperature, and light exposure, as they are the main threats to the viability of your seeds. We’ll break down the need to control each of these below:
Low Moisture
Both the seeds and the storage environment should be kept dry. Moisture content should be minimized to extend the seed’s viability. The actual moisture content of the seeds also affects the temperature and length of storage they can endure.
Low to Freezing Temperature
Seeds store best at low temperatures. For prolonged periods, freezing marijuana seeds at -4 F (-20 C) is recommended. If you are storing marijuana seeds in this manner, ensure they are vacuum-sealed to protect against excess moisture and humidity levels.
Zero Exposure to Light
Light exposure can trigger germination processes within the seed, leading to degradation or nonviability when it comes time to try for germination. Specifically, UV light can cause seed degradation by causing photochemical reactions that break down or into the seed husk over time. Store your seeds in an opaque, airtight container to ensure they remain in darkness.
Common Issues When Storing Cannabis Seeds
Don’t Keep in Your Main Fridge
The main fridge is subject to frequent temperature changes since people are constantly opening and closing the door and putting potentially warm foods there, which can harm the seeds. Use a dedicated cooler or freezer that gets opened minimally for more stable conditions to ensure stability.
Label Clearly
Always label your cannabis seed collection with the cultivar name and the date of storage. This helps you keep track of their age and viability and understand where you may be in potential breeding projects.
Vacuum Seal if Possible
Vacuum-sealing fresh seeds minimizes their exposure to air and moisture, significantly extending their storage life. When air is left in a container, it allows some variability in the environment surrounding your seeds (i.e., the air), which can cause ice crystals to form when freezing, triggering germination. Vacuum-sealing gives your seeds the best chance at staying alive while dormant in storage.
When Weed Seeds Don’t Germinate
Seeds, like siblings, are not all created equal, meaning some may be more resistant to errors during the germination process than other seeds.
The three pillars of seed germination are proper temperature, moisture content, and patience. If either of these fluctuates too much, it will affect the viability of the seeds. The most common errors novice growers will make are related to moisture content or getting too impatient. If your seeds are stubborn and don’t want to germinate, try one of several techniques, such as scarification, hydrogen peroxide, or stratification.
When soaking seeds to prepare them for germination, letting them sit in water can cut off oxygen, making it more difficult for them to aerate. Conversely, a lack of moisture is typically caused by a heat source that dries out the medium in which the seeds are placed.
Conclusion
Storing cannabis seeds correctly is within your reach; you need to know what variables to control to achieve the desired outcome. By understanding and applying the proper storage conditions—dryness, stable low temperatures, and darkness—you can preserve your stored seeds’ viability for the long term. Happy sowing and growing!
Sources used in article
- DeBacco University. (2021, March 26). How to store cannabis seeds [Video]. YouTube. https://www.youtube.com/watch?v=JLyHzZnIvRg
- Suriyong, S., Krittigamas, N., Pinmanee, S., Punyalue, A., & Vearasilp, S. (2015). Influence of storage conditions on change of hemp seed quality. Agriculture and Agricultural Science Procedia, 5, 170–176. https://doi.org/10.1016/j.aaspro.2015.08.026
- Parihar, S. S., Dadlani, M., Lal, S. K., Tonapi, V. A., Nautiyal, P. C., & Basu, S. (2014). Effect of seed moisture content and storage temperature on seed longevity of hemp (Cannabis sativa). Indian Journal of Agricultural Sciences/Indian Journal of Agricultural Sciences, 84(11). https://doi.org/10.56093/ijas.v84i11.44551
Hi, I recently took advantage of buy 10/get 10. I plan to keep some seeds long term. In the keep moisture section it says to keep in an airtight container. Under FAQS it states never to store in plastic or an airtight container but to store in an envelope. I’m confused. I plant to keep in the refrigerator so what container should I use? I am not familiar with glass containers that do not have either plastic lids or metal lids??
Back again to clarify I did put a desicant pack in the plastic container but my old fridge had issues and thawed slightly a couple times. I have 5 strains of my own creation. Seeds were very ripe and dark striped. Fingers crossed that the other 4 strains are as hardy.
I have seeds in sandwich bags sealed in seal a meal and stored in a plastic jar covered in black tape in the freezer at -5 farenheit dated 2009. 11 year old seeds that a test batch sprouted in 2-4 days at at least a 95% success rate. Blew me away!
So do we store in an airtight container? as it says at the end ” . Never store seeds in a plastic bag or airtight container. ” however above that it states using an airtight seal is a great way to keep moisture low
What about keeping the seeds in the little plastic containers you sent them in and put them in a glass Ball jar with a plastic lid and store in a dark place
That article gave me a headache trying to figure out whether seedds should be in an air tight container or not. Someone needs to write a clear and coherent article about seed storage.
I’ve never seen a cannabis seed sink until they’ve been in the water for about an hour or so your article stars they should sink lol
I’m considering storing auto gorilla seeds in Infinity Jars. food-grade, Black Ultraviolet Glass with BPA free Plastic screwtop airtight lid.
Maybe a ball jar sealed with silica pack then place in the fridge within a light-blocking container.
This article says in one breath to save the seeds in glass jars, then later says store seeds in plastic and never use airtight containers… huh?
If i use glass jars, then how do i not make it NOT airtight. Regular mason jars that have glass and a metal cover won’t do?. Do i need a special jars or leave the cover not perfectly fully sealed.
I’ve kept my seeds in original plastic baggie, in an envelope in our safe. Dark, cool and dry. None of the 5 seeds I have sprouted. Soaking in purified water for a 10 day period on the kitchen counter. None of the germinated.
Maybe I’m stoned (I am but that’s not the point)but doesn’t this article contradict itself several times? Freeze-bad, then freeze-good, airtight-yes, then airtight-no, plastic-yes, then plastic-no. I gotta know this stuff, especially when I take advantage of your buy 10 get 10 deals!
This context is confusing, its from your article on storing seeds:
How do you know if seeds are still good?
Place cannabis seeds in water, if they sink they should be good to go, if they sink they will most likely not be able to sprout.
Great stuff, can you clarify or correct the statement “How do you know if seeds are still good?
Place cannabis seeds in water, if they sink they should be good to go, if they sink they will most likely not be able to sprout.”
Robert,
You say to stay away from plastic containers. What about a vacuum seal type of plastic container that was made for long term storage of plant material/weed? I have an opaque green and purple plastic container that I purchased to transport so, the smell did not permeate the car. Works very well. Will this type of container work for long term storage of seeds? Seems like it would be a good choice with some silica gel packets in the container. Your thoughts???????
Can I get a grow kit with girl scout extreme cookies
I would love this guide
Could I leave the seeds in what you guys send them in if I was to put the hole thing in a black jar?
thanks for the tips bob,,i was doing one thing wrong with my seeds,,now i keep my seeds in a, C vault container in a down stairs fridge ,keep tips coming
In the article above, it says to use Moisture removing packets or cooked rice To keep out moisture. Don’t you mean un-cooked rice?
I have froze seeds in the package that they were shipped in. Not for more than 3 years and have them germanait.I don’t know if I’m Lucky or what. But my man Robert knows more than I. Rock on I.L.G.M.