Cannabis seedlings usually emerge from the growing medium 24 to 72 hours after the germinated seeds are planted.
Place another few layers of moist tissue on top of the seeds, again allowing excess water to drain off.
Place the cannabis seed, root first, into the hole and cover with a small amount of growing medium – just enough to block light, not enough to obstruct the seedling when it emerges.
Step 3. Potting – How to germinate cannabis seeds
Seeds should be placed on top of the tissue, allowing each seed as much space as possible.
Place the plates somewhere warm (21ºC) and away from direct light.
Lastly, cover everything with the second plate, upside down, to form a ‘clam-shell’ shape – this will create the dark, moist environment necessary for germination.
Check the seeds every day to ensure that the tissue does not dry out. Spray the tissues with water if necessary.
If you find that you need to rehydrate your seed container, place the entire pot in a basin with 2 to 3 inches of warm water and allow the planting medium to wick moisture from the bottom. If just the surface has dried, you can lift the plastic covering and spritz the surface with water from a spray bottle. As soon as the seeds germinate, remove the plastic wrap.
Most seeds will not germinate without sunlight and will perform best with 12 to 16 hours each day. Indoors, place seed containers in a sunny, south-facing window and give the container a quarter turn each day to prevent the seedlings from overreaching toward the light and developing weak, elongated stems. Also, gently brush the palm of your hand against the tops of the seedlings to encourage strong stem growth.
Once you are ready to sow, you can test the viability of many, but not all, seeds by soaking them in water for a few hours. The seeds that are still living will sink to the bottom, while the dead ones will float on the surface. This test generally works better for larger seeds, but there are no absolutes.
7. Keep seeds warm to encourage germination
The fungal infection often referred to as damping-off is usually caused by excessive moisture and poor air circulation. However, there are a few cultural techniques that will help to keep fungal agents at bay. After covering the seeds with planting mix and tamping them down, spread a thin layer of 50 percent milled sphagnum and 50 percent starter chicken grit (finely ground stone) over the surface to keep the soil around the emerging shoots dry and provide an inhospitable environment for pathogens.
Seeds are a fragile commodity, and if not treated properly, their viability will sharply decline. While some seeds may survive for thousands of years under the proper conditions, others will lose viability quickly, even when properly stored. To maintain dormancy, keep seeds in a cool, dark location with low humidity, like a refrigerator. I recommend labeling them (seed name, source, year) and storing them in a small reclosable bag or empty film canister that is, in turn, kept in a larger plastic container.
To promote good air circulation, place a small fan near your seedlings. Keep the fan on low and direct it to blow across the containers at the soil level where air may become trapped and stagnant.
An often overlooked aspect of plant propagation is the art of record keeping. Whether you are producing a few plants for your home flower and vegetable gardens or working at a larger-scale nursery, developing a propagation journal will prove indispensable. Here at the Center for Historic Plants, we record when seeds are sown, the germination date and success rate, and when seedlings are ready for transplanting each year.
For most types of seeds, this is our go-to gardening secret! 🙂 Germinating seeds in 1/3 time with 3X more success, yes, you have to try this!
It is important to have pots and soil ready to go.
Our favorite method to germinate seeds super fast with much more success.
The slowest seeds to germinate are pepper, eggplant, fennel, celery, which may take 5+ days. The rest such as tomato, beets, chard, squash, onions, will take about 3 days.
Our favorite seed companies are Baker Creek Seeds, and Everwilde Farms both are started and ran by some great passionate people! Just look at that gorgeous green corn from Baker Creek, irresistible!
Start checking on them the next day. If the seeds are really fresh, some will germinate in as little as 1 day! The fastest germinating seeds include everything in the cabbage family – bok choi, broccoli, kale, cauliflower etc, and lettuce.