Cannabis Seed Storage: Best Practices for Longevity  

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Any cannabis growing project starts with seeds. You need to buy a pack of seeds of the desired strain and germinate them for further indoor, outdoor, or greenhouse planting. While this stage is easy to cover – you can always find tons of excellent variants of top-quality seeds at AskGrowers.com – the most challenging question is what to do with seeds you haven’t managed to use up. 

It's common for growers to save money on the seeds' purchase and buy them in bulk, so how can you store them until the next season without ruining their vitality? Here is a brief guide on seed storage that will help even inexperienced growers to protect their seeds from deterioration.   

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Proper Parameters for Seed Storage 

As your seeds are alive, they should be kept in special conditions to germinate successfully months or even years after production. Here are the key characteristics of your environment that affect seed vitality. 

Humidity 

High humidity is essential for seeds' germination; that's why one of the common germination methods is the wet paper towel technique. Seeds become alive and develop sprouts at 80-100% humidity, but their storage in the non-activated form requires much lower humidity levels. Experts recommend an 18-20% humidity level for medium-term storage and 12-14% for long-term storage. However, it's vital not to reduce humidity levels below 10%, as 8-9% humidity is already disastrous for seed survival. 

Light 

You might be surprised to know that the thick, non-transparent seed shell doesn't protect the seed's embryo from light. Thus, the risk of seed death is very high if you store the seeds in a well-lighted environment. Just think of the natural processes of seed germination: a seed is thrown into the soil, where it spends a cold winter in a dark environment and starts reviving in warm, moist soil without access to sunlight. The sprout gets to the sunlight only after it germinates and gets out of the soil, so exposing seeds to light may be highly destructive for their germination potential.  

Oxygen Access 

Since seeds are living beings, they need oxygen to breathe, though not as much as people do. Thus, it is vital to provide them with minimal oxygen access for the period of storage; don't vacuum your seeds before storage, as this may ruin them. 

Temperature 

Seeds are stored better in colder temperatures, and most experts recommend storage at 40C as the optimal parameter. Obviously, this is not a one-size-fits-all approach, as seeds can survive (and thrive) in a much broader range of temperatures. However, the rule of thumb is – the lower, the better. Your seeds will last longer if they're stored at, say, 100C than they will under the temperature of 200C. Some reputable seed banks even store seeds in freezers, which doesn't hurt the seed's embryo and allows the seeds to survive for many years. Thus, you can also put your seeds in a freezer and store them at -150C to -200C for a steady supply of seeds for the next growing season. 

Pro Storage Tips 

Once you get the fundamentals of seed storage, you may become more proficient in protecting your weed seeds until the next growing season. Here are a couple more tips for helping you organize the storage of your dream. 

• Label and date the seeds. It's unnecessary if you have only one bag of seeds for the next season. However, if you're a weed connoisseur growing many varied strains and collecting seeds every year, it's better to make a clear label to avoid confusion. 
• Organize a solid container. Those who store seeds in a fridge or freezer may accidentally throw some food packaging on the seeds, thus crushing them and ruining their seed supply. Thus, it’s advisable to keep the seeds in a solid plastic container to ensure they don’t get accidentally spoiled. 
• Dry the seeds before storage. Statistics show that seeds germinate much better if they are exposed to preliminary drying before packaging and storage. So, if you collect the seeds from your own plantation, make sure to arrange 1-2 months of proper drying conditions and then transfer the seeds into a cool, dark, and cold environment for long-term preservation. 

Cannabis Seeds Q&A 

Let’s briefly cover some more issues that weed enthusiasts often encounter in the process of planning storage for their seeds or evaluating the quality of stored seeds. 

What Is the Best Way to Store Seeds? 

The optimal storage environment should be a dark, dry, and cool place. It's also necessary to avoid fluctuations in the storage conditions, such as light or temperature variations during different times of the day or varying seasons. One of the suitable options is a refrigerator; you can use a thick black plastic or paper coating for the seeds and place them in a distant corner that won't experience temperature fluctuations when you open the fridge from time to time. 

How Long Can I Store the Seeds? 

If you arrange the proper storage conditions (a cool, dark, and dry container with a stable environment), your seeds can serve you for up to 5 years (and even more). Many expert growers who store seeds in properly insulated containers enjoy high germination rates and good yields even after 5 years of storage, so you can start with 1-2 years and then extend the storage period to see how it goes. 

Can Cannabis Seeds Get Spoiled? 

Yes, cannabis seeds are exposed to deterioration, like any other organic matter. This happens even in the conditions of well-planned storage if they stay unused for many years. However, the seeds can get spoiled even faster if exposed to light, temperature changes, or accidentally get moist. 

What Is the Optimal Storage Temperature for Weed Seeds? 

Weed seeds feel the best when they are stored at a cool temperature but are not frozen. The optimal conditions are from 210C to 320C, but this temperature is fine for the seeds you’re planning to germinate soon. If you prepare the seeds for long-term storage, keep the temperature even lower (a fridge is a good option). 

Organize Your Storage Wisely 

As you can see, proper seed storage can provide you with viable seeds for years to come. One round of weed pollination can be more than enough to give you a rich stock of seeds for planting, and you won’t need to spend extra money in a seed bank or dispensary. Follow these tips and tricks for safe, intact storage arrangement under proper conditions, and you’re sure to enjoy high germination rates and impressive yields almost infinitely. 

The author of this article is Tia Moskalenko, a cannabis advocate, researcher, and blogger at AskGrowers. Tia is continually exploring new ways of growing cannabis to share her findings with people interested in this niche. She prepares insightful articles and instructional guides to make the entire process of weed planting more efficient and productive.  

*This article is not to be interpreted as a statement of any form by Spliff but merely a compendium of information compiled from other sources. These statements have not been evaluated by Health Canada, FDA or any other regulatory body. Consult your doctor before ingesting or smoking any herbal product.*