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How Long do Weed Seeds Last?


There is plenty of online discussion about how long do weed seeds last before they won’t sprout. Some claim that they can last for many years if they are kept in the proper storage conditions. Others disagree and say that they can only be planted within 1 year or so after harvesting. So the burning question that everyone wants the truth about is, how long do marijuana seeds really last?

In some instances the latter claim may be proven to be true, if they are weak or immature seeds have been kept in poor storage conditions. How long your marijuana seeds will last depends completely on how you store them. If the seeds are stored in damp conditions or exposed to constant light, they will die from being damaged internally. It should also be noted that weed seeds are fragile and should be protected from the risk of being crushed.

Will Cracked Marijuana Seeds Still Germinate?

Unfortunately, once the shell cracks the inside will dry out completely and the seed won’t germinate. It cannot be viable as the internal mechanism of the seed that passes on the genetic information of the plant is damaged or dead. Good seed storage practices should be used to prevent seeds from getting physical damage related to unnecessary negative exposure.

Weed seeds can last very long periods of time in proper storage, as long as they are well cared for. An environment with low humidity levels with no light and cool temperatures will work best to preserve your seeds for a year or so. If you want to store them long-term, then they must be refrigerated.

Are White Weed Seeds Good or Bad?

If the seeds are white, or pale green, they were harvested prematurely and they are unlikely to sprout.
If they are pale from being stored in the light too long, the slower they will germinate.
The darker the seed colour, the more likely they are to sprout and produce a viable weed plant. The dark shell indicated the seed is mature and ready for use.

How Long Do Weed Seeds Last Before They Go Bad?

As we discussed before, marijuana seeds can be made to last a very long time if they are refrigerated. Without any outside negative interference, weed seeds can last a few years if they are kept in a cool, dry and dark place, but if they are stored in constant refrigerated conditions, weed seeds can last up to a decade.


How Long Do Weed Seeds Last With Refrigeration and Extra Dry Conditions?

This will vary greatly as no one can keep perfect conditions outside a laboratory usually. If great care is given from the time they are harvested, protected from humidity and light, and provided a cool environment the genetic material at the center of the seed will stay dormant, making the weed seed last longer. Generally, if you refrigerate them at home, expect them to last about 5 years, 10 if you never open the refrigerator or lose power.

Why your Cannabis Seeds Haven’t Germinated?

If you haven’t been successful with getting some or all of your weed seeds to germinate, there is usually an answer. Germination isn’t only getting your seed to crack and a taproot developing, it’s about the changing of a dry seed into a very small but viable weed plant. So let’s try to figure out what went wrong.


How long did you soak your weed seeds?

Did the seeds sink to the bottom of the presoaking container before putting them into the moist paper towel? If your seeds are still floating then they still need to sit a while longer to absorb more water. Seeds that are still afloat when transferred to paper towels are less likely to successfully germinate. Also, be aware that soaking them too long will stop the growth of the taproot since it doesn’t have to search for water.

Did the paper towel dry out at any time?

At the first stages of germinating a weed seed, the smallest of mistakes can have major consequences. The paper towel mustn’t be soaked in water. The taproot will search out water as it grows naturally. If the paper towel is saturated it’s too easy to find and the taproot will stop growing. If you use contaminated water it just won’t grow. Contaminants such as chlorine and chemicals on dirty hands can poison your seeds.


Keep your workstation sterile when working with seeds. Also, keep your hands washed and covered with latex gloves. The next component to optimize is the temperature of the seeds. The best temperature to keep them good for germination is around 72 degrees Fahrenheit or 21 to 23 degrees Celsius. If the seeds are still refrigerated they just won’t begin to germinate until they reach optimal temperatures.

The roots of the weed seedlings don’t like light and the same applies to the taproot when your seeds begin to germinate. Complete darkness is ideal for germinating any seeds no matter what the plant.


Have you ever found an odd seed somewhere at the bottom of an old weed storage bin? Here are a few tips on how to ensure germination of that old cannabis seed:

Pre-soak your cannabis seeds to improve germination rate.

Before germinating your old seeds, you can try soaking them in one of the following:

  • carbonated water enriched with fulvic acid,
  • germination booster,
  • hydrogen peroxide, or
  • gibberellic acid.

For top results, use room temperature rainwater and soak your seeds for 12 to 18 hours in a dark place.

Nick you cannabis seeds to increase germination rate. (Scarified seeds)

Put a small cut(nick) in the seeds with the edge of a pair of nail clippers. A nail file or a piece of sandpaper can sand through the seed’s edge. Make a very shallow cut on the seed, just enough to allow water to penetrate the seed casing. Be careful to avoid damaging the seed embryo – you want to cut just through the seed casing while leaving the seed’s embryo and other seed structures uncut.

Nicking cannabis seeds to increase germination rates.

*Don’t Store Scarified seeds because they can quickly lose the ability to sprout.

So, why should you nick your cannabis seed casings? Nicking your seeds before germinating helps the seeds absorb liquid, which tells the plant embryo to start the germination process. Nicking marijuana seeds and then soaking them in water will increase the speed of them sprouting. This technique is also referred to as scarification.


Scar your cannabis seeds to increase germination rate.

Older marijuana seeds often have an extra tough outer casing. Gently scratching the shell of the seed casing with a fingernail file can help water enter your seed to increase germination rates. Try gently sanding your old cannabis seed shells just before soaking to help them sprout.


Remove a seed’s ridge

The ridge is the elevated side of your seed as shown in the picture. Like other parts of the seed shell, this ridge can become extra tough after a long time in storage. Removing it gently with a razor-sharp blade can help your seed sprout and grow.

Don’t forget, some old marijuana seeds just won’t sprout no matter how much love you give them. Whenever possible, avoid buying more seeds than you plan to grow so as to avoid having any problems at the time of germination.

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