i don't know if you want to consider this a tip, i don't know of any scientific proof to validate it, but it did work for me, it really can't hurt...i read in a thread on this site about the "banana religion", i don't want to post unproven info, but i got 3/3 females, first time grower,
i found this when i googled it:
The Banana Religion
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I call it a religion because I
believe this works; I have no scientific evidence that it does. It is a religion because it is not factual, otherwise I'd call it a science.
Don't ask me for links because I don't have any, but in my time here I have read that marijuana plants' sex is not determined until the plant is 3 to 4 weeks old. I have also read that ethylene gas influences plants to be female. That's all plants, not just marijuana.
All ripening fruit gives off ethylene gas and bananas and apples are supposed to be high in ethylene gas as they ripen. I prefer bananas.
So - as many of you have seen - I put a banana at the base of a plant I want to be female. I put it there when the plant is 3 weeks old & keep one there for two weeks. I'll keep one there until it turns black - I don't want bugs - then I put a new one down if needed. I've had success with 4 plants (out of 4) that I have tried putting a banana under. Another member of GC is 2 for 2 and now I have a banana under my current plant.
Bananas are cheap - cheaper than feminized seeds! It may be a crazy idea, but I'm interested to hear of any other "banana trials".
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I changed my bananas well before get the black, no mold at all, and used a total of 2 bananas per plant, cost me like a buck total to try this