They need warmth ~ 80°F I don't believe in that method even though lots of peeps do it that way.
I know that a lot of growers swear by it and their proof is the fact that many plants survive the technique but unless seeds are old or have been stored poorly soaking seeds is not needed and can drown them. Then because they need the instant gratification of seeing the tap root they germinate them in paper towels. If you look at a tap root under 200x magnification you will see the “root hairs” that grow laterally out from the tap root. These become the plant’s uptake roots. They will grow into the fibers of the paper towels and are ripped off every time the seedling is move or the towel is opened – ouch. Then when transplanting it is very easy to bump the tap root tip and damage it or kill the seedling – Why?
Put the fresh or properly stored seed ½” deep in a Rapid Rooter, Root Riot, rock wool cube or similar or right in the soil. Don’t use Jiffy peat pots the PH is too low. Keep moist – not wet, and ~80°F, 60% humidity with your blue (veg) lights on and they will germinate if viable. I use 25% strength week one nutrients with a little kelp to moisten my starter cubes. Most strains will germinate in 5 to 7 days. Some strains take longer than others. The African sativas can take 21+ days so be patient. If your seeds are not fresh or have been stored poorly an 8 hour soak in a weak kelp solution can encourage germination. Kelp has natural
Gibberellic acid GA3 which is a growth stimulator.
5 plus year old seeds require special treatment. As the seeds age the outer shell becomes denser making it harder for water to penetrate and stimulate the growth. A slight scuff on a piece of super fine sand paper or the striker on a match book will cut into the surface of the shell. The idea is to make sure the seed gets enough water inside before it drowns. A few minute rinse in H202 will sanitize the outside of the seed. Then proceed as above.
Old TimingMan germinated 40 year old seeds using this method:
“ Old TimingMan
I wish there was a easier way but so far my best luck has been scuffing them in a sandpaper tube, letting them set in a H2O2 bath for an hour while plunking them down every 15 minutes, and then using the GA3 at a rate of 500 PPM in distilled water with temps at the 80 degree mark from soak to sprout.”