Best Way To Rescue Cannabis Old Seeds

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The seeds are made up of a hard outer shell and an embryo that is inside the hard shell. It contains a large amount of genetic material, within that small object is the future of the organism. And like animals, the fate and end result of the seed depends almost entirely on how it is treated in its early stages of life. Food and the environment will be very important factors for proper development. But this becomes more noticeable when we try to rescue old seeds genetics or we try to start our project with seeds that have difficulty germinating.


For millennia farmers have collected the seeds and stored them under favorable conditions until the next sowing season, thus ensuring their survival through the winter. The germination inhibition mechanisms that allow seeds to survive winter before germination are often lost with domestication. Seeds of wild varieties tend to germinate slowly and unevenly due to natural adaptation to climatic fluctuations from year to year, while seeds of domesticated varieties germinate quickly and evenly. The wild characteristic of germination inhibition is no longer an advantage in a domesticated variety. Today’s farmers prefer and choose rapid and uniform germination.

All seeds are alive when they come from their mother plant. There is a plant in every seed and as long as it is alive the seed will grow even if they are old. The reason that older seeds do not germinate well is that the shell has become too hard and water cannot penetrate the shell, this process known as imbibition is the beginning of the germination process. To germinate seeds that are difficult to start or that have problems germinating you have to have a little patience. Since a seed can take between three days and three weeks to germinate.


Three important things affect the viability of an old seed: Age, Seed Type and Storage Conditions. All seeds remain viable for at least one year and most will be viable for two years. The germination rate of the seeds will start to decrease after the first year and especially if the storage conditions have not been good. The external appearance can give us some key information to know the age of the seed. A dark and bright color, which is perceived when the seed is exposed to light, will indicate that the seed is still viable. When the seeds are old they crack or fall apart when pressed.

We use sterilized gloves and tweezers to touch the seeds. To improve the chances of success it is essential not to touch the seeds directly with your hands. Touching the seeds with your hands could contaminate them with pathogens, fungi or bacteria that could unfortunately spoil your seeds.

The type of seed affects how long a seed remains viable. Some seeds like corn or peppers will have a hard time surviving beyond two years. Beans, peas, tomatoes, and carrots can remain viable for up to four years. In our case, the seeds of indica strains remain viable for less time than the seeds of sativa strains, even taking an average of between 2 to 5 years of viability. In some cases it has been possible to germinate cannabis seeds with more antiquity, up to 7 to 10 years, but it is the least likely since it depends 100% on the last factor.

Without doubt the most influential factor is the storage conditions. The old seeds will stay viable for much longer if stored carefully. Ideally, they should be stored in an airtight, opaque plastic container along with silicon gel to reduce humidity. The perfect conditions are between 6 – 8º C and a relative humidity between 20/30%. These conditions must be kept constant and without variations over time in order to achieve maximum effectiveness and viability in our seeds.


As long as the small latent embryo that lives inside the shell does not detect moisture, it will not know that the right conditions exist to germinate. This process is called imbibition or initiation of germination. If the seeds have been stored for a maximum of 2 years, they should not give us any problems in the germination process. But the longer the seeds have been kept, the older they will be and the harder the shell will be. This complicates and lengthens the germination process as moisture will take longer to penetrate the shell.

Due to the risk of losing genetics, at Tropical Seeds Co we have developed and used several techniques that help the old seeds in this process and will maximize the number of individuals that we will have available for our project. To improve the chances of success it is essential not to touch the seeds directly with your hands. Touching the seeds with your hands could contaminate them with pathogens, fungi or bacteria that could unfortunately spoil your seeds.


One of the most popular techniques among growers is to hydrate the seeds by soaking them with water. You have to watch out with this technique since it has some limitations to consider when putting it into use. First of all, it is important to bear in mind that if we use water for human consumption, it will contain chlorine and other chemicals that could affect our seeds. If we want to favor this process, it is advisable to use 000 ppm water and try to keep it between 20 and 24º C avoiding direct light throughout the process. It is convenient to know that acidic Phs favor imbibition, so a Ph of 5.5 will help our seeds to start germination in a more optimal way.

The most important limitation of this technique is given by the time that the seeds can be submerged without reaching oxygen deprivation, approximately 24 hours after being submerged. To prevent the seeds from being drowned, it is good to add Oxygenated Water (Hydrogen Peroxide) at a rate of 1ml per liter. Other supplements can also speed up the germination process. Adding to the water Root Stimulator, CO2, Gibberellic Acid GA3 (0.1%) or Fulvic Acid (5ml / L) contributes to the absorption of water, you can also provide a light dose of nutrients without exceeding an EC of 0,4.


Gibberellic Acid is a hormone that occurs naturally in plants. This acid promotes growth, regulates development, and stimulates plant cells, as well as increasing the germination rate of old seeds as it interrupts the dormancy period. We can find this acid on the market in a purified form as a white crystalline powder and soluble in ethanol.

To prepare our Gibberellic Acid solution we will need the following materials:

  • 0.1 grams of Gibberellic Acid
  • 5 ml of Isopropyl Alcohol 70% Ethanol
  • 95 ml of water 000 ppm
  • Useful for mixing
  • Opaque pot

Since it is a very powerful hormone, it is applied in low concentrations. Take the 0.1 grams of Gibberellic Acid and dissolve them in the 5ml of Alcohol. Once it is dissolved, you just have to add the solution to the 95 ml of water and let it rest for 2 hours. This resulting solution is 100 ml at a proportion of 0.1% Gibberellic Acid. As long as we keep this solution in a cool place and without exposing it to light, it can last for several years without losing effectiveness.


Although some expert growers manage to keep for several days until the seeds have sprouted the perfect conditions of the hydration process with the old seeds soaked; adding Hydrogen Peroxide, changing the solution every few days, maintaining the temperature, etc. This would not be the most recommended due to the difficulty involved and because in the event of any problem, it could affect all the seeds at the same time. We recommend that after the first 24 – 36 hours the seeds be transferred to a germination tray with an opaque lid.

It is the classic technique of the two plates placed in the shape of a UFO but taken to the extreme and for that we must be totally careful with the hygiene and sterilization of the materials that we are going to use. If we are going to use kitchen paper to make the seed base, it is advisable to look for recycled paper, white paper contains chlorine and other chemicals that could affect germination. We will always use sterilized gloves and tweezers to touch and move the seeds, it is important to keep in mind that the less you touch the better. So I recommend that you be delicate but confident when it comes to grabbing the seeds.

The idea is that the old seeds remain in the germinator until the germination process is advanced enough for the seeds to be transferred to the substrate. As we have said previously, each seed will take its time in this process. For this reason, hygiene and conditions of high humidity and stable temperature are now more important than ever. Any failure can cause the rapid development of a fungus or pathogen that would end the life of our seeds. Before the appearance of any problem, we will have to be quick and as soon as possible remove the seeds that have had the problem. In addition, we will change the paper inside the germinator for a new one and we will place the remaining seeds again so that they continue the process.

With this technique and changing the paper for a clean one every few days it should be relatively easy to keep some old seeds in the germination process for up to one or two weeks, enough time for the seeds that were in better condition to come forward. But if all else fails, you still have the ability to scrape the shell off with sandpaper, creating micro-abrasions that will let more water into the embryo. And although it is not the most recommended, as a last hope we can still open the shell very carefully, leaving a small opening through which now, surely, water will enter the shell and hydrate the embryo.


At this time, with the maximum number of seeds showing their roots, they can pass to the final final substrate where they will develop the first weeks of life. We like to follow the rule of less is always better than more. We will hydrate the substrate slightly before the seed is transferred with the root down without burying it too much, you can perfectly leave the seed sticking out of the substrate. If you also only use between 25 to 50% of the pot with substrate, we will avoid in the first stretching of the plant that it is too outside, simply as it grows we will bury the trunk until the pot is completed.

If the number of old seeds that have germinated is small, it is always more convenient to use a greenhouse for the first days until they show the cotyledons, at which time they can receive direct light without problems. In the case of having many seeds, it would be convenient to maintain a very high relative humidity during the first days around 80% and a ventilation and soft light. Gradually as the first real leaves begin to show, at which point we will increase the ventilation and the amount of lumens.

And we leave a final think… Do you think that the current genetic decline is negatively affecting the reputation of the seed bank sector or the way the sector respects the grower is negatively affecting genetics? Thinking back … Breeders who never raised a male? 10 new hybrids per season? Bulk quality at outrageous prices? Really … is this what the public asks for or is this what is offered? It gives a lot to think about.

No matter what type of seed you are trying to germinate, the quality of your seeds can make it even better. Explore our seeds and feel free to contact us if you have any questions to or our Live Chat. Continue reading another of our posts that may be of interest to you; The authentic cornerstone of Breeding: Local or Pure strains, The importance of Male Cannabis Plant, Unbelievable Bomb: 100 Seeds Packs.

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