Most people growing from seed and looking for a high CBD mother will probably spend several months bringing a plant to harvest before sending a flower sample off to a lab for testing to find out CBD/THC/etc levels.
This can be especially disheartening for medical users with neither time or money on their side, to waste several months only to find that their plant has no CBD.
But the cannabinoid profile is genetically determined, and you can access it from the first true (non-cotyledon) leaves. You can send it off to a lab of course, but it's far cheaper and quicker to simply use Thin Layer Chromatography in your own home.
No flowering period required, just 2-3 weeks of seedling/vegetative phase, a little bit of luck, and some Thin Layer Chromatography. A CBD blitz.
And because we're only dealing with small seedlings and such a short time frame, this makes it possible to quickly grow out seeds, and while a small grow chamber may only be large enough to bring 1 adult plant to harvest, it would still be big enough for a dozen or so seedlings. Then after 3 weeks you simply do the chromatography tests, keep the plant(s) you want and cull/discard the rest.
You only need:
Method:
For info about Thin Layer Chromatography see [this icmag thread] and [my DIY@Home tutorial]
___________________________________________________
Ok, so we start out with seeds that claim to be high CBD and low THC, and I decide that of the ~30 or so that I've got I want to run 16 on the first "blitz"...
Fortunately all 16 germinated. I simply used cheap plastic drinking cups as the pots (some guys here have grown to harvest in those so i knew they'd be fine!). Unfortunately i forgot to add perlite to the coco coir, and only drilled one small draining hole which proved insufficient.
I could only have them under 12/12 lighting for the first two weeks, and here they are at 14 days ... this is about as early as I'd want to cut:
I had planned to take them to a full 3 weeks, but I stopped two days short on day 19, as I was getting drooping leaves from the poor aeration. Easy to fix next time.
So here they are on day 19 just before The Snip ... you can also see their letter ID that I use to assign lanes in the chromatography...
I simply take one of the trifoliate leaves from the outside of the container (where it has had no interaction with leaves from other plants).
Lanes:
A - Thunderstruck #3 (by Sin City) (non-symmetric growth)
B - Thunderstruck #2
C - Thunderstruck #1
D - Thunderstruck #4 (weird mutant)
E - Thunderstruck #5 (ingrown leaf)
F - Dinamed (by Dinafem)
G - Candida #2 (by Medical Marijuana Genetics)
H - Candida #1
I - Cannatonic #1 (by Resin Seeds)
J - Cannatonic #5
K - Cannatonic #3
L - Cannatonic #2
M - Cannatonic #4
N - Harlesin (by Sin City)
O - CBD Therapy #1 (by CBD Crew)
P - CBD Therapy #2
Now, the Thin Layer Chromatography ...
Here was the first run ...
The next morning I did another run just to help confirm some ...
Results
CBD only - THC only - THC+CBD
A - Thunderstruck #3
B - Thunderstruck #2
C - Thunderstruck #1
D - Thunderstruck #4
E - Thunderstruck #5
F - Dinamed
G - Candida #2
H - Candida #1
I - Cannatonic #1
J - Cannatonic #5
K - Cannatonic #3
L - Cannatonic #2
M - Cannatonic #4
N - Harlesin
O - CBD Therapy #1
P - CBD Therapy #2
I will now cull down from 16 to 4 ... (D, G, H, O). Because G & H seem identical one of those is likely to be culled also.
(Yes, i prefer THC with my CBD too, but if you just have a CBD-only strain it's easy enough to add THC "on the side" as an optional extra from another plant, plus you can provide it to family members who may only want CBD and no THC etc).
Other thoughts...
Dinamed: This is the 3rd time ive grown Dinamed. The first time was a 1:1, but the other two times were THC-only. Disappointing.
Candida: My first grow of this, and both were CBD-only, excellent result.
Cannatonic: Very disappointing to not get any CBD detection, just THC.
CBD Therapy: This is the 3rd time ive grown CBD Therapy, I've ended up with two 1:1's, and one CBD-only, so that's a pretty good return. Mosts tests put these phenos of Therapy at 20 - 25:1 [link]
Thunderstruck: Three of the five showed a form of mutation, i wonder if that's because it's a selfed S1. Either way, it was good to see them all return healthy levels of CBD, but all in the 1:1 range except for the main mutant which is CBD-only. It'll be interesting to see how it grows, because it reminds me of a Blueberry mutant i had which stopped growing after a month.
This can be especially disheartening for medical users with neither time or money on their side, to waste several months only to find that their plant has no CBD.
But the cannabinoid profile is genetically determined, and you can access it from the first true (non-cotyledon) leaves. You can send it off to a lab of course, but it's far cheaper and quicker to simply use Thin Layer Chromatography in your own home.
No flowering period required, just 2-3 weeks of seedling/vegetative phase, a little bit of luck, and some Thin Layer Chromatography. A CBD blitz.
And because we're only dealing with small seedlings and such a short time frame, this makes it possible to quickly grow out seeds, and while a small grow chamber may only be large enough to bring 1 adult plant to harvest, it would still be big enough for a dozen or so seedlings. Then after 3 weeks you simply do the chromatography tests, keep the plant(s) you want and cull/discard the rest.
You only need:
- Seeds
- Small pots (or plastic/foam cups
- Grow chamber or sun or sufficient lighting
- Thin Layer Chromatography equipment (see [my DIY TLC link])
- 2-3 weeks time
- A bit of luck with the genetics - seeds are dice!
Method:
- Germinate the seeds.
- Grow for 2-3 weeks (until they're big enough to take a leaf cutting).
- Cut a trifoliate leaf off each seedling.
- Use gloves to prevent cross-contamination of samples.
- Wrap individually in aluminium foil.
- Decarboxylate for 60 mins @ 125°C/257°F, to convert THCA to THC etc
- Use Thin Layer Chromatography to determine CBD and THC levels in each one
- Keep the good ones, cull/discard the rest.
For info about Thin Layer Chromatography see [this icmag thread] and [my DIY@Home tutorial]
___________________________________________________
Ok, so we start out with seeds that claim to be high CBD and low THC, and I decide that of the ~30 or so that I've got I want to run 16 on the first "blitz"...
Fortunately all 16 germinated. I simply used cheap plastic drinking cups as the pots (some guys here have grown to harvest in those so i knew they'd be fine!). Unfortunately i forgot to add perlite to the coco coir, and only drilled one small draining hole which proved insufficient.
I could only have them under 12/12 lighting for the first two weeks, and here they are at 14 days ... this is about as early as I'd want to cut:
I had planned to take them to a full 3 weeks, but I stopped two days short on day 19, as I was getting drooping leaves from the poor aeration. Easy to fix next time.
So here they are on day 19 just before The Snip ... you can also see their letter ID that I use to assign lanes in the chromatography...
I simply take one of the trifoliate leaves from the outside of the container (where it has had no interaction with leaves from other plants).
Lanes:
A - Thunderstruck #3 (by Sin City) (non-symmetric growth)
B - Thunderstruck #2
C - Thunderstruck #1
D - Thunderstruck #4 (weird mutant)
E - Thunderstruck #5 (ingrown leaf)
F - Dinamed (by Dinafem)
G - Candida #2 (by Medical Marijuana Genetics)
H - Candida #1
I - Cannatonic #1 (by Resin Seeds)
J - Cannatonic #5
K - Cannatonic #3
L - Cannatonic #2
M - Cannatonic #4
N - Harlesin (by Sin City)
O - CBD Therapy #1 (by CBD Crew)
P - CBD Therapy #2
Now, the Thin Layer Chromatography ...
Here was the first run ...
The next morning I did another run just to help confirm some ...
Results
CBD only - THC only - THC+CBD
A - Thunderstruck #3
B - Thunderstruck #2
C - Thunderstruck #1
D - Thunderstruck #4
E - Thunderstruck #5
F - Dinamed
G - Candida #2
H - Candida #1
I - Cannatonic #1
J - Cannatonic #5
K - Cannatonic #3
L - Cannatonic #2
M - Cannatonic #4
N - Harlesin
O - CBD Therapy #1
P - CBD Therapy #2
I will now cull down from 16 to 4 ... (D, G, H, O). Because G & H seem identical one of those is likely to be culled also.
(Yes, i prefer THC with my CBD too, but if you just have a CBD-only strain it's easy enough to add THC "on the side" as an optional extra from another plant, plus you can provide it to family members who may only want CBD and no THC etc).
Other thoughts...
Dinamed: This is the 3rd time ive grown Dinamed. The first time was a 1:1, but the other two times were THC-only. Disappointing.
Candida: My first grow of this, and both were CBD-only, excellent result.
Cannatonic: Very disappointing to not get any CBD detection, just THC.
CBD Therapy: This is the 3rd time ive grown CBD Therapy, I've ended up with two 1:1's, and one CBD-only, so that's a pretty good return. Mosts tests put these phenos of Therapy at 20 - 25:1 [link]
Thunderstruck: Three of the five showed a form of mutation, i wonder if that's because it's a selfed S1. Either way, it was good to see them all return healthy levels of CBD, but all in the 1:1 range except for the main mutant which is CBD-only. It'll be interesting to see how it grows, because it reminds me of a Blueberry mutant i had which stopped growing after a month.
