Told you in the previous post that I’d be back for the sexy stuff, now here we are.

Quick re-hash, these are F1 seeds I’m running, a cross of In House Genetics’ Silky Johnson F2 and a CookieWreck (Cannaventure) x Biker Kush (Karma Genetics) cross.  I’m growing them in lava rock within a rubbermaid container that’s plumbed into a small bio filter and mounted over a fish tank

In terms of difficulty, I find sexing cannabis a bit challenging. Both for general nature, the signs are small and ambiguous, and for variation, every plant behaves differently.

If you’ve ever worked with fruit flies, I feel sexing those are much easier. Reason being, the differences between the sexes are obvious. Female fruit flies are larger, and more hairy. To determine their sex, you need to anesthetize the flies and put them under a microscope. While under, some egg-carrying females may actually lay their eggs, right under the microscope; which leaves little room to wonder about their sex.

With cannabis, sexing is slower, and less clear. You’re looking at the branching points along the main stem, or nodes, for the growth of the plant’s sexual organs. Often, the nodes along the plant are not of equal progress, some nodes will show something that looks like male pre-flowers, and some won’t.

Males are more difficult to spot early on, I find. I look for females, and mark them once they’re found. I pinch the plants stem, rotating it back and forth, looking for a white filament, sticking from the node.

Here is one certain female:

Female Plant

For the males, I just track them. Once I’m certain they’re male, I clip their stem close to the base, and throw the plant in the garbage. You want to cull the males before they start to form pollen, so they don’t pollenate the rest of your female plants. For this grow, I’d like to give time for the plants time to fill in the space previously occupied by the male, so I’m pretty keen to get them early.

Here is one suspected dude:

Probably a guy
Leaf discolouration

I am seeing some discolouration on larger fan leafs, particularly those below the canopy. Could be related to light penetration, or senescence; it’s more likely related to nutrients, but the problem isn’t pervasive across all plants and nodes. Because this is really an exercise about cleaning a fish tank, I’m less concerned about correcting the issue, just going to ride it out.


This grow is out in the open, its in the basement. I’m not using a timer, I just turn the light off around 3:30pm (I usually remember), and on again, usually between 6-7am. I could install a timer in half the time it took me to write this sentence, not bragging, and it’s a problem I should correct before it causes further problems.


Thanks for reading the post today. I’ll be back when all the males are culled, and the remaining females are about halfway mature. 

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