There are a whole lot of things that can prevent cannabis seeds from germinating. Here are some of the most common reasons why your seeds may not “pop”:
Keeping the above in mind, seeds do need moisture to germinate. Keep your soil moist but not damp. The best approach is to use a hand sprayer with a fine mist setting. Use a transparent germination hood or cling film to keep the soil from drying out.
1. BAD SEEDS
If your substrate drains poorly, excess water in the soil will prevent your seed from accessing oxygen, and it will encourage fungal growth. You can improve the water drainage of your soil by adding some perlite. Also, always make sure your planting containers have holes in the bottom for water to drain out.
For more information on storing your cannabis seeds properly, see our blog on How To Preserve Seeds.
Use bottled water for germination. If you need to use tap water, fill a bucket with hot water and let it sit outside for a day. This allows the chlorine to evaporate so the water is safer to use for germinating.
If all else fails, there are still a few more aggressive tricks that should only be used when, after a few days, your seeds have failed to hatch and make their way into the world.
For example, you can scrape off the outer layer of the seed with a little sandpaper, creating micro-abrasions that should let some water in. So you don’t overdo it with this scraping we have a little trick: roll up a piece of very fine sandpaper, with the rough side on the interior, and secure it with tape. Place the seeds inside and cover the openings with your hands. Then just shake it for a couple of minutes and the sandpaper will do its job. Another more risky option is to use a knife to cut the seed transversely, ever so slightly, which will help the water penetrate the shell.
Another good investment, which can be key in the case of old seeds, is Jiffy 7. This product is a compressed pill of dried peat that you need to soak for a few minutes. At this point it becomes a small sack of soil that is specially designed to facilitate germination, because it features the ideal structure, is sterilized, has all the necessary elements to nourish the seedlings during the first week, and is pH-neutral. Due to these characteristics it can be your best bet to get your older seeds to sprout.
Other good choices for germination
For all this you will need an airtight container or canister, or an opaque plastic bottle in which, in addition to the seeds, you should place little pouches of silica gel, to reduce the moisture. With regards to the best place in your refrigerator, the crisper is a good choice, as it is a little warmer than the rest of the fridge. Also, one last tip: if you store several strains in different bottles, it is a good idea to label them, so that you won´t have to open them to see which is which when you decide to plant them.
If you have only saved the seeds for a year and a half, they should not give you any problems. After this time period, even if you have stored them properly, germination may be more complicated because the older the seeds are, the harder their shells, so the water used to open them will take longer to penetrate them. Therefore, the first method to try to get the plant’s embryo to develop is to put your old seeds in a glass of water, with a few drops of hydrogen peroxide, for 24 hours. Hydrogen peroxide softens the shell and facilitates the water’s infiltration.
First, you have won half the battle if you were careful with the original storage. Seeds must be kept in a cool, dry place. Therefore, the best option is to store them in refrigerators at a temperature between 6 and 8 degrees Celsius, and with relative humidity levels between 20% and 30%. And sheltered from light, of course.
But you must be careful: the liquid must not be cold, but rather at a temperature of around 22° C. And you must keep the container away from major sources of light. During the 24 hours that the seeds are there you will have to keep a very close eye on them in order to remove them quickly if they open, so they don´t “drown.”