Criteria for selecting breeding males?

This is question for anyone who is or has ‘intentionally’ grown male for making seeds.

What are the criteria that you use to select the phenotype of a male with in a strain specific group of regular photo seeds.

The things I usually look for are shorter bushier males who go into flower the fastest, ‘assumption’ being if the male flowers quickly then so might the female.

I look for ones that were the healthiest of the group, resistant to pests or allergens.

Since they came for a group of same strain males and female, I compare the smell of the terpenes to see if they are a match.

One other thing, I don’t personally think that you can successfully sex a seed, the plant must be grown.

Let me know, and the thanks as always.
@MrPeat, @Covertgrower, @blackthumbbetty, @AAA, @repins12, @ILGM.Roy, @Haildamaged, @Myfriendis410, @Cannabian


I’ll include @Bogleg in this response as well.

Terpenes some have a more desirable terpenes than another male.
Ability to take root after cloning.
Growth tracking, which shows better structure etc.
How will the male pollen sacks develop, and structure. @Stonedrus


For me it will be the healthiest and biggest for males. I watched a video on YouTube where he had planted like 48 plants outside and he pulled all the males he thought was weak. He judged it by how tall and healthy the plant was as. The rest he pulled and got rid of.


I used to choose the earliest males, but DJ Short believes that earlier males are better suited for fiber production and not medicine. After hearing this it makes sense. I believe if you grow out a strain for say 5 years and let natural selection take place the medicinal quality would drop. The plants evolutionary directive is not necessarily the same as our desires hence selective breeding on our part.

  • Look for hollow stems- sign of high THC content
  • Internode spacing- want it to be tight
  • stem rub
  • look for trichs under scope
  • dry hit a male flower doob or Vape some male flowers to judge flavor

The biggest mistake made is not letting the males fully mature. Some plants go into overdrive later and being able to see them through the entire flowering cycle is the best way to judge them.

Node spacing and distribution, not sure I’m a fan of fast flowering but understand why.

I had a Gold Leaf that every row of main stem branches were 120 degrees apart (3) and the next row of branches would start 60 degrees out from the previous ones which avoided preferential shading of the canopy.


I have seen plants that are more hollow and less woody. does this really correlate to THC content?

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I tend to pick the healthiest male out of the bunch. It depends a bit on the intent. If I were breeding for indoor it would be different than for outdoor. Ideally, health is number 1, if the male is strong and resilient thats a good trait. Do I want a bybrid or a heritage? Am I breeding for smell/ taste/ strength / height? I guess I find the question too difficult to answer with anything definitive.
Since I like to grow outdoors/greenhouse, big plants are good, so small males are weeded out. Since I prefer, less skunky/musky smells I will weed them out. Because I live in BC we get colder sooner than California so I need a cold tolerant plant, one that resists mold and pests. It seems that males always flower way earlier than females and I need to collect pollen anyway so I dont really care about that. To be honest, since my Mexican seed has become useless as I took a long hiatus from growing, Im rebuilding my seed stock… now that weed is legal! So this summer is all about breeding and if I get seedy weed so be it, all the better. I will be growing multiple plants and cull all males except the 2 best ones! They will be Johaars and Northern Indian. No modern hybrids.

I looked at all the morphological traits, the general vigor of the plants, and things like smell and resinous feel. I’d even ingest them looking for effect.

The outward indicators meant little, compared to growing out generations of their offspring. I still believe the only way to select the best males is to keep them going as you breed out their clones.

According to DJ Short, yes, hollow stems equate to higher THC levels. I have no personal experience though.

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I do know that one of the strongest plants I have ever grown did have a hollow main stalk and branches. But that was 25 years ago and I don’t have real data to prove or disprove. I will search for it.

I had a male that did this. @AAA

Thought hollow stems was just a Ca deficiency?

@Budbrother I’ve read more from the genetics end than anything. But that doesn’t mean I could be wrong.

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I always culled them for being weak and not good for breeding stock

@Budbrother DJ short says the contrary.

Also I have heard Duke Diamond mention hollow stems in a positive way.

I would love to read about it, @AAA

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It’s in his book.


Thanks @AAA!


My pleasure. I need to drop his seeds. I have Flo F5, Blueberry F5, and First Light.

Same, blueberry, and “ limonene queen”… that was the freeby. @aaa

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