In a life or death situation, surgery may be the only option. Meaning—only do this if nothing else has worked because this technique ruins as many seeds as it saves.
Keep the water warm, but not too hot. Aim for around 22°C. Avoid direct sunlight, and keep an eye on the glass. Do not soak seeds for prolonged periods, more than 24 hours can deprive them of oxygen and make them drown.
The seed’s shell is made up of two pieces, with a seam going all around. The side that’s raised more than the other is the ridge. A hardened ridge can make it difficult for the seed to open. To remove the ridge, run a sharp blade along the ridge on both sides. Handle gently and it should come off without damaging the inside of the seed.
4. SLICE THE SEED
If you’re going to keep seeds more than a year or two, proper storage will dramatically increase the chances of late-stage germination. Place them in an airtight container. Put the container in a refrigerator set at 6–8°C with 20–30% relative humidity. If excess moisture is a concern, add silica gel packs to the container.
As cannabis seeds age, their protective outer shell hardens and prevents water from passing through. Unless the tiny, dormant embryo that lives inside the shell detects moisture, it doesn’t know that the conditions are right to sprout. As a first step, pre-soak your old cannabis seeds for about 12 hours to see if that does the trick.
When your old cannabis seeds don’t want to pop, one of these four techniques could come to their—and your—rescue. Aging seeds are more difficult to grow than fresh ones and we’ll explain what you can do to help germination.
Scarification, or scuffing the shell, can also help water pass through an older seed’s tough outer shell.
For stubborn seeds, place them in a glass of water with a few drops of hydrogen peroxide for about 24 hours. The hydrogen peroxide will help break down the outer shell and get water into the sprout where it’s needed. Once the seeds are done soaking, take them out of the mixture and rinse, then follow up with the soil or paper towel method.
One of the best, and most readily available, places to store seeds long term is to stick them in a refrigerator. Ideally, you don;t want to freeze the seeds, as any moisture that may be contained inside can crystallize and harm the future seedling. So, keeping them at a cool 6-8 degrees Celsius (42-46º F) is far better than a deep freeze. That will pretty much obliterate the heat element.
Tried and true, Mother Nature seems to know what she’s doing. This method is pretty much how it’s done with just about any type of plant, not just marijuana seeds. Essentially- you plant the seed. Water. Wait. Pretty straightforward.
Water & Hydrogen Peroxide
Another way to coax the shell to break down a bit is to add some fulvic acid to your original water source. A concentration of about 10ml/L is suggested. Fulvic acid is a natural component of healthy soil. It’s an organic polymer that is extracted from humus. It helps further facilitate the breakdown of the marijuana seeds outer shell and also encourages healthy plant growth.
You might find yourself asking “How long do marijuana seeds last?” This is a great question, and the answer almost solely depends on the methods of preservation. Depending on how you’ve stored your seeds, they can essentially last indefinitely.
As they say, not all heroes wear capes, and absolutely zero of them toss old seeds.
To discourage any light from getting in, place the seeds in an opaque container. While it’s unlikely that the seeds will enjoy much sunlight in your crisper drawer, placing the seeds in a small container means that you can more readily control their immediate environment. On top of shutting out light and excess moisture, place small bags of silica gel in with the seeds. This will help prevent any excess moisture build up, effectively keeping your seeds viable for extended periods of time.