actuly I'm growing in my room and my plants are on 24/0 and I heep the temp at 20C at all timesindirect light for the first week to let them adjust. Direct light will lower humidity and you want to keep humidity high. Im assuming your talking about rooted clones. If your talking about rooting them then you would be better to use a floro in a 100 humid environment. Your greenhouse will be too hot to do this since your going to need to put them under a humidity dome and your already in a greenhouse so the heat will be too much.