When stored properly, cannabis seeds can still be viable for up to five years or more after being harvested. Stored seeds should be kept away from light, moisture, and fluctuations in temperature. In essence, seeds should be stored in cool, dark places.

How to Store Cannabis Seeds

One of the critical things in ensuring the continued viability of your surplus seeds is to store them properly. While cannabis seeds have tough outer shells, the truth is that they are vulnerable to environmental factors such as humidity, light oxygen, and changes in temperature. Exposing them to these conditions will compromise their stability, making them hard to germinate. Here are ways to preserve your cannabis seeds properly.

Ideal Conditions for Storing Cannabis Seeds

The three main threats for cannabis seeds are light, increased temperature, and humidity. Thus, a cold, dark, and dry location is vital in maintaining the viability of your seeds. Exposure to light and high temperatures will trigger your seeds to use up their essential nutrients before you can germinate them. This means that they won’t have the nutrients needed to grow and produce high-quality crops. High moisture levels, on the other hand, can create a breeding ground for fungi on your seeds, which can have dire effects on their longevity and viability.

How Humidity Affects Cannabis Seeds

This is one of the chief enemies when it comes to weed seed storage. Exposing your seeds to excessive moisture will make them a target for fungi and also promote premature germination. Here is how different humidity levels affect the quality of your marijuana seeds.

  • 80-100%: Seeds will drown and wilt after 12 hours
  • 40-60%: Seeds will start germinating
  • 18-20%: Heating may occur
  • 12-14%: The growth of Bacteria and Fungi both in and outside of the seeds
  • 8-9%: This moisture level may attract insects on the seeds

Ideally, the moisture percentage of your seed storage area should be between 6-9%. This percentage is perfect for long term storage as very low humidity levels can lead to the death of your seeds.


Cannabis seeds should be stored in cold places, and therefore locations that are near the floor are more ideal than those nearer the ceiling, which could be warmer. For short term weed seed storage, you can place your seeds in a dark cupboard so long as the storage facility is in a location with little temperature fluctuations.

However, long term cannabis seeds storage is best achieved by placing the seeds in the fridge or freezer. Ensure that the storage container is air-tight and avoid opening your fridge so frequently. Moreover, consider putting your seeds at the back of your refrigerator where least moisture is available. The ideal temperature for long term preservation is 4 degrees. Resist the temptation of removing your seeds from the refrigerator or freezer too often as the fluctuation in temperature will have adverse effects on the seeds.


Just like temperature and humidity, the light will cause premature germination of your cannabis seeds, compromising their potency.

Storage Containers for Marijuana Seeds

It is vital to establish the recommended containers for the storage of your weed seeds. The storage jars must be air-tight and vacuum proof, which serves to prevent the penetration of light or moisture. For short term storage, you can use black canisters as they are wholly lightproof and are fitted with a good seal.

However, for long-term cannabis seeds storage, it is important to obtain glass or metal containers with lids made from their corresponding materials. Avoid plastic storage jars whose porous nature will allow the moisture to penetrate damaging your stored seeds.

Silica gel can also be used to stabilize moisture levels in the storage containers. Nevertheless, you should not use too much desiccant as extremely low moisture levels could be detrimental to your seeds. Note that the weight of the silica gel should equal the weight of the seeds.

In as much as possible, endeavor to keep your seeds in their original packaging to preserve their effectiveness. If that is not possible and you need to open the packaging to get some seeds, place them in a paper envelope before transferring them into a container. Such a seed envelope allows the trapped moisture in the seed to escape before storing.

Marijuana Grow Guide

The Best Seeds to Preserve

Necessarily, the healthier the strain, the longer the stored seeds will remain viable. However, it is critical to examine the seeds before preserving them regardless of their strain. Watch out for cracks or any surface damage which could significantly reduce the longevity of the preserved seeds. Any dented seed should be planted as soon as possible to boost its chances of germinating. Marijuana seeds should be properly dried before being preserved. Failure to dry the seeds completely may lead to molding and decay due to the moisture residual in them.

You can test if your acquired seeds are completely dry by putting them in a jar and placing them on a countertop for a few hours. If you notice condensation inside the container, this means that the seeds are still moist and need to be dried further. Dry your seeds using a desiccant and place them in air-tight jars. Ensure you label your containers to avoid confusion in the future.

The labeling should include the strain of the cannabis seed, the number of seeds in the jar, and the date of storage. If you plan to preserve your seeds for an extended period, consider placing the label inside the jar to save it from fading or falling off.

The Germination Rate of the Preserved Seeds

It is vital to note that stored marijuana seeds do not germinate as readily as the new seeds. Older seeds will take longer to grow, while others may never sprout at all. As such, it is recommended to buy small packages of seeds if you do not plan to plant many seeds at a go.


The truth is that not all seeds you purchase will be planted at that particular season. You are bound to have some leftovers, and it is vital to store them properly, adequately stored seeds can last for years, and this is critical, especially when you want to retain a particular strain of marijuana. Contact us to learn more about cannabis seed strains and their storage. Our team of experts will answer all your questions concerning cannabis seed storage and germination.