Cannabis

I hope you are only partially trimming the tips as you may be suppressing flower formation. One week of distractions could get pollen and then seedy harvest. Another year learn to take cuttings, you can test flower the cuts before they even root. Just put them on 6 or so hours of light, 16-18 hours of darkness per day will get the cuttings to show gender. That way you can start with more seeds and pull the males early. You can even keep a few male cuttings and flower them tiny, harvest the pollen and selectively pollinate just a small bud area on a couple of plants.