However, slight patience is required when conducting the float test, as results are not immediately apparent. You’ll have to wait for approximately 1–2 hours before confirming the results. Some good-quality seeds will need adequate time to absorb enough water for them to sink. Use this time to go water the garden and get some much needed pruning done. Upon your return, any seeds that remain on the surface are most likely not viable and won’t be worth further time and effort.
This simple and cost-effective method is a great way to tell the good genetics from the bad; they will sink or swim, literally. Seeds that remain buoyant on the surface are more than likely of poor quality and are to be discarded. Seeds that sink to the bottom like a botanical cannonball are probably healthy and should be germinated.
The fact that cannabis seeds can vary in appearance has led some growers to think that the size, shape, or color of a seed dictates its quality.
Conducting The Float Test
Some smokers might be pleased to see some cannabis seeds in their bag, and might think themselves lucky. However, finding seeds in a bag is bad for various reasons. For one, this means the grower has messed up and allowed their female plants to be pollinated by an invading male. When flowers are pollinated, they stop producing THC-containing resin and divert their energy toward producing seeds. Secondly, the seeds will have added to the overall weight of the bag, which means less weed for your buck.
It’s important to only conduct this test if you are planning to germinate the seeds immediately afterwards. The viable seeds that sunk to the bottom of the glass will have taken in water, crossing the membrane of the seed and signalling that it’s time to come to life—activating germination.
We hear this question all the time from clients and beginner growers, and the answer is a resounding no. There is simply no way to tell the sex of a cannabis seed just by looking at it.
Mature cannabis seeds usually have a hard outer shell that can vary in color from very dark (or almost black) to very light grey and may have tiger-like stripes. You should be able to firmly press these seeds between your fingers without damaging them.
How long your seeds will last can vary. If great care is taken for the seeds to be protected from humidity and light, and provided a cool environment the center of the seed will remain dormant, making the marijuana seed last longer. That way, the only thing needed to germinate the seed will be to soak them overnight in water then place them in a damp tissue or Jiffy plug and germinate normally.
As we mentioned before, marijuana seeds can be made to last very long if they are refrigerated. Without any interference, marijuana seeds can last a few months before they go bad, even up to a year if they are kept in a cool, dry and dark place, but if they are refrigerated, marijuana seeds can last up to a decade.
There is plenty of debate surrounding how long do marijuana seeds last before they go bad. Some people say that they can last for years if they are kept in the correct conditions, while others disagree and state that they can only be used within 6 months to 1 year after packing. So the question is, how long do marijuana seeds last?
How Long Do Marijuana Seeds Last Before They Go Bad?
Unfortunately, the answer to will a cracked seed still germinate is No. It cannot germinate as the valuable internal part of the seed that contains the genetic information of the plant is exposed, then the seed will no longer germinate. Great care must be taken to ensure the seeds are not damaged or crushed, including putting them in vials stuffed with cotton wool to ensure they don’t rattle around and harm each other.
Cannabis seeds can withstand long amounts of time in storage, as long as they are well protected. A cool, dark environment with no humidity or strong aromas is good to store the seeds for a few months, but if you want to extend the shelf-life of the seeds, then they must be refrigerated.
In some cases the latter may be true, if they are weak genetics or the seeds have been kept in adverse conditions. How long the seeds will last depends totally on the conditions they are stored in. If the seeds are humid or exposed to light, they will not germinate from being damaged internally. It is also essential to add that the seeds must be protected from being crushed.
So, how long marijuana seeds will last depends on the care you take to conserve your marijuana seeds in the correct way. If you are very careful marijuana seeds last you for ages. You can even stock up on strains to have your own collection and at the same time, remain self-sufficient throughout the year.
Marijuana seeds should be kept in a cool, dark place such as a basement or in your refrigerator. They should be in an air-tight container and must stay dry. Putting a cotton ball in with the seeds before storage can help suck up any extra moisture (this is why you often see little bits of cotton in seed breeder packs).
Heat and moisture ‘signal’ to cannabis seeds that it’s time to sprout, so as long as you keep the seeds in a dry, dark environment they can remain viable for years. I have heard cases of seeds sprouting after being in storage for 5 or even 10 years. However, you will notice that older seeds take longer to germinate than fresh seeds and a few of them may not sprout at all. As time goes on, fewer and fewer of the seeds will successfully germinate.