Easy guys/gals whatever the case maybe...We are all friends here, what works for one person may not be the best for someone else. Cannabis seeds will germinate in a wide range of temps 70F-90F. However, high temps will upset the seed chemistry and low temps will delay germination. Cannabis grows best at 78F according to Jorge Cervantes Marijuana Horticulture indoor/outdoor growers bible...
Here are some of my notes on some seeds I just finished germinating using many different technigues...I hope they help.
Seed Germination: Paper Towel Method
This will be a record for germinating seeds using the “Paper Towel Method. Using 7-14 paper towels sheets stacked up top of each other then moistened with tap water, peel back half of the paper towels and insert seeds a then put the folded paper towels with seeds into a plastic zip lock bag…I will be closing the bag air tight.
06 June @ 6:30am:
Filled a gallon pitcher with tap water and then let it stand for 36 hours, or so…Adjusted the pH to around 5.8-6.2.
07 June @ 7:37pm:
I soak the paper towels in the pH adjusted water. Dropped the folded paper towels into the water then pulled them right back out and squeezed out enough water that the paper towels do not drip. Unfolded wet paper towels and then inserted the seeds. Then placed paper towel with seeds into plastic bag, sealed the bag with a puff of air (breath) and placed it in the garage, in a dark location, where the air temps range from 75F-85F…Temp 80F
07 June @ 11:00pm:
Checked for any early cracks and sprayed some water on them because they felt a little dry. I may have squeeze to much water out of the paper towels to start with. No problems, No cracked seeds. Temp 79F
08 June @ 6:30am:
No cracked seeds, Temp 77F
08 June @ 2:10pm:
No cracked seeds, Temp 78F
08 June @ 9:40pm:
One cracked seed out of Seven, Temp 77
09 June @ 10:30am:
All seeds have cracked!
It took about 36 hours for all seeds to crack…I have placed all 7 seeds in 1.5 Rockwool cubes that have been soaking in pH adjusted water for 48 hours.(Usually 24 hours is enough, got lazy) I did not use the pre-drilled holes for it is very hard to get the taproot turned down and seated at the bottom. Plus, did not want to damage the taproot so I used the a wooden stick to agitate the surface of the Rockwool cubes like soil. I then buried all seven seeds 1/8”-1/4” deep, taproot down, in the Rockwool cubes. The Rockwool cubes were then placed in a 10”x20” tray with cube holder insert.
09 June @ 6:10pm:
Seeds are in the 1.5 Rockwool cubes in a dark location…I will give them light as soon as they sprout through the Rockwool, if they do? Fingers crossed!
Temp 81
10 June 9:30am
3 of 7 seeds have sprouted…And due to a mistake on my part the entire seven seed pods are now receiving light from 4-26 watt CFL, 6500K…Due to the lights being on at the same time the heat pad was on the Temps once again shot into the 90’s, with a Temp of 93F
10 June @ 9:45pm:
No changes, 3 of 7 have sprouted and look good…Temp 82
11 June @ 7:00am:
WOW! All 7 seeds have sprouted! Temp 76
...And my little Rockwool experiment:
Seed Experiment: Using 1.5” Rockwool cubes to germinate seeds.
I am testing for the best way to germinate seeds using 1.5” Rockwool cubes w/holes. The focus of this experiment is to find out if the predrilled holes in the Rockwool cubes are best used as:
*A) they are, meaning drop the seed down the pre drilled hole(1/2” -3/4” deep) and use a small wooden stick to seat the seed at the bottom of the hole and leave the hole open.
*B) or, use the wooden stick to close the hole by agitating the Rockwool fibers as one would a growing medium such as soil, so that the seed is completely entombed or buried in the Rockwool.
*C) or, completely do away with the pre drilled hole by agitating the surface of the Rockwool cube as done in part B but prior to putting the seed in it. So that the hole is completely filled with Rockwool fibers and the surface is “tilled up” like soil…Then place the seed in the Rockwool and cover it with Rockwool fibers about 1/8”-1/4” deep in the cube.
I am using 18 1.5” Rockwool cubes that were pre-soaked in a pH balance solution, 6 cubes will be used in each Part A; Part B; and PartC…
07 June @ 4:20pm:
All 18 cubes have been placed in a 10”x20” humidity dome in a dark room. The humidity dome was placed on a “NEW” seedling heat matt.
07 June @ 6:30pm:
I may have damaged the seeds! The new heat matt shot the temp inside the humidity dome to 98F…I unplugged the NEW heat matt. The seeds were only subjected to these extreme temps for maybe 2 hours…?
07 June @ 7:07pm:
The temps with the humidity dome are back down to 80F…I will monitor the temps closely to keep them within the ideal range for germination(70F-90F)…I try to maintain 75F-80F.
07 June @ 11:30pm:
No early birds and no problems…Temp was 79F
08 June @ 6:30am:
Checked for any signs of early germination, there was none. No problems. Temp was 77F
08 June @ 1:30:
Nothing yet; Temp 78F
08 June @ 9:40pm:
One seed within group A has visibly cracked; Two seeds in group C have visibly cracked and appear to be breaking the surface of the Rockwool…Nothing in group B. Temp 76
09 June 10:30am:
No changes in regards to the seeds. I have placed the seed tray w/humidity dome back over the heating mat with 1” plastic pegs between the mat and the bottom of the seed tray. This appears to have been exactly the height needed to maintain the desired temperature range of 75F-80F. Temp 80
09 June @ 6:10pm:
Had to lift the tray higher off the heat mat, 2 inches, due to temps climbing back up to 90F! The temps are back to 81F…Will monitor closely.
10 June @ 9:30am:
What a difference a night makes! OK, in Group A there is no sprouts; in group B 1 of 6 have sprouted; in Group C 5 of 6 have sprouted; So, it appears the method used in group C is clearly the better method to use if using Rockwool for germination…Even better than the “Paper Towel Method”!
*Due to an error of mine all the cubes are now under lights, 4 26 watt CFL’s, 6500K…And the temps were in the 90’sF this AM because the heat matt was still on. Temp 93
10 June @ 9:45pm:
No changes in regards to new sprouts…However, the temp is back down to 83F.
11 June @ 7:00am:
WOW! It is clear that plants do the majority of their growing during the dark cycle…Group A 3 of 6 have sprouted; Group B 4 of 6 have sprouted; Group C 5 of 6 have sprouted. Temp 76.