One of the most common reasons seeds fail to germinate is because they are simply duds. Typically, healthy cannabis seeds should look a specific way and be of a specific colour. Viable seeds will appear round, not flat, and should be a beige to dark brown colour with subtle tiger striping. Seeds that have been flattened or are pale in colour may have a tough time sprouting into healthy cannabis plants.
Many people choose to germinate their seeds using paper towels. However, others choose to do so directly in soil. Of course, germinating your seeds in soil isn’t inherently bad, but it can come with its own set of challenges, and is generally not recommended unless necessary.
GERMINATING BAD SEEDS
There are some techniques that can be used to ensure your seedlings remain in this temperature range. Some growers choose to use special warming mats that can be set to a specific temperature and placed underneath the seedling containers. Another strategy is to place a timed heater close to your seedlings to warm them up occasionally. Once your seeds have sprouted, they will be much more resilient to fluctuations in temperature.
Seeds that have been improperly stored may also fail to germinate. These tiny packages of DNA prefer to be kept in a cool, dark place with moderate humidity. Exposing them to heat, light, or extreme humidity levels (both high and low) could result in seeds losing their viability. As long as you source your seeds from reputable seedbanks and store them appropriately, you shouldn’t have to worry about bad seeds ruining your chances of successful germination.
Cannabis seeds require a specific temperature range in order to germinate. Regardless of the germination medium you are using (soil, paper towels, etc.), the temperature in the environment should consistently sit in the 26–28℃ range. Seeds need to be kept warm during the germination process. At no point during germination should seeds be exposed to temperatures below 20℃.
Once they have sprouted, they will need a lot of light — 18 hours a day, to be exact (though you could even give them 24 hours of light per day).
But you don’t need any propagator at all.
no additional equipment required (assuming you have paper towels)
requires transplanting the seeds, which risks damage
need to ensure the paper towel stays damp, but not wet
For this method, place a paper towel on a plate and get it nice and wet. Drain off any excess water, though. It should be damp, but there should be no standing water or the seeds can drown.
no transplanting required
no additional equipment required
lower success rate than other methods
• Nutrient burn
Cannabis seedlings are super fragile and can easily “burn” in nutrient-rich soil. In general, we don’t recommend feeding during the seedling phase. Instead, keep your seedlings chilling in their Easy Start pots until they’re ready to be transplanted and start vegging.
Once you’ve transplanted your seedlings into their new pots, give them 3–7 days to adjust. Remember, transplanting is a stressful process, and your plants will need some time to recover from it. Feed your plants too early after transplanting, and they likely won’t take up all their nutrients from their medium, which can cause problems (like nutrient lockout) further down the line.
HOW TO AVOID NUTRIENT PROBLEMS
• Glass of water method
Three simple steps to mastering the cannabis seedling stage.
Finally, to minimise the chance of a Pythium, Botrytis, or Fusarium infestation even further, be sure to always use new soil or sterilise your soil by baking it in the oven until it reaches a temperature of 85°C.