Germinating Cannabis Seeds (for Bio Growers)
Your seedlings will be alot better off if you germinate directly in soil - less handling and mechanical disturbance means less chance of physical damage to the plant's taproot (and roothairs) and less food reserves used to position itself due to the natural hormonal influence called Gravitropism - that spells seedling VIGOR.
This is my foolproof method for Cannabis Seed Germination in soil:
First, if harvesting seeds from my own crosses, I air-dry newly harvested seeds for a couple of weeks, and then store them in the refrigerator with a little rice. Cold-treatment seems to increase viability and germination rates, especially with indica-dom strains. I almost always get a 100% germination rate with quality seedstock.
Soak the seeds in plain water for at least 12 hours prior to planting to hydrate them, which will speed up germination. In general, good seeds will sink, bad seeds will remain floating (they contain air, not an embryo). I first sterilize seeds in a bleach solution (1 Tbsp. bleach/1 gallon of water) for 1/2 hour to kill any fungus residing on the seedcoat. Dump the sanitizing solution and top off your glass with clean water, you do not need to rinse those seeds.
Sterilize enough *damp* fine soil with heat to germinate all of your seeds. You can do this by treating the damp soil to temps of (no more than) 200F for 20 mins in a conventional oven, or in a microwave oven on high for 2 minutes, while stirring a couple of times. Your goal is to get and hold the entire soil mix's temperature at 170F to 180F for about 20 minutes which can be monitored with a probe type thermometer. Let the mix cool thoroughly. This will insure that damp-off fungus spores have been killed in the soil mix. Make sure the soil mix is light and humusy (not real coarse). You can add a little sand or vermiculite to aid in drainage and weight. Stay away from perlite, it has a nasty habit of floating out of the mix (if you do indeed need to water later).
Buy some white 20oz styrofoam "drinking glasses", commonly called "Styro-Cups", and punch holes in the bottom (and side bottom) for drainage. I use a red-hot ice pick for this. These containers are 6 1/2" tall and will allow ample room for the taproot to grow before cotyledon emergence which will increase your seedling's vigor. The taproot (radicle) is already at least 4" long at the point of emergence - don't restrict it in order to maximize seedling growth rate. Styro-Cups can be found on the shelf displaying picnic items at your local grocery store.
Fill the pots almost to the top with your soil mix, water well to settle the mix, take a pencil and make a small hole about 1/4" to 1/2" deep, NO deeper, and drop *one* seed in. Cover the seed with *fine* soil, only enough to top up the hole, firm lightly with your finger, and lightly water until water runs freely thru the drain holes. Place in a warm spot around 80F/26C. Do NOT cover the cup with saran wrap or anything else. The seed has been hydrated from the soaking and will germinate soon. This container should not require further watering until the seedling is up and running.
During the first couple of days, mist the top soil surface lightly if need be, never allowing the top to crust over, but not to the point that the medium stays waterlogged which will invite pythium rot. "Less is more" at this point. Do NOT water this pot any more until the seedling is up, and only if it needs it at the point of emergence and do NOT mist the seedling once it is up as you're inviting damp-off disease if you do. Again, no need to cover with plastic wrap as the radicle (taproot) will grow at least 4" before the cotyledons emerge from the soil. IOW, even though you can't see it, the plant's root is seeking and finding moisture at the container's lower soil levels. I cannot emphasize this enough. The seedling will emerge anywhere from 2 to 10 days from the time you sow it.
That's all to it! With good care, your faves will be ready to transplant within 1 to 2 weeks, and will easily slip out of the "cup" with a solid rootball that will never know it's been disturbed if potted up gently and quickly. Move up to a final pot of 3 to 5 gallons to sex and finish.
Good luck,
Uncle Ben
