During flowering, most photoperiod cannabis plants stop stretching after around 4-5 weeks. Finding a hermaphrodite in your growroom can happen at any stage of the flowering cycle and is indicated by the presence of male flowers growing on the same plant as female flowers. Most seed banks online offer this service and will be more than happy to provide it to you.  Source: <a href="https://ipllive2018.com/7-cfr-201-16-noxious-weed-seeds-digital-code-of-federal-laws-e-cfr-lii-legal-information-institute_922851.html" rel="nofollow">https://ipllive2018.com/7-cfr-201-16-noxious-weed-seeds-digital-code-of-federal-laws-e-cfr-lii-legal-information-institute_922851.html</a>