Once the cuttings have callused, reduce the mist as much as possible without letting the cuttings wilt. Callus formation should be evident by day 14. Avoid excessive ventilation early in the propagation cycle as this can dehydrate the cuttings. Once the cuttings have begun rooting, air circulation will help tone the cuttings and get them acclimated to harsher finishing conditions. The cuttings should have a good root system by day 21-27.
Some growers dip the base of the cuttings into a rooting hormone.
Poinsettias will root without the use of a rooting hormone, especially under optimum environmental conditions. However, the use of rooting hormone may encourage uniform rooting process under less than ideal conditions or with difficult to root cultivars. Apply growth regulators early in the morning or in the evening when you can turn off the mist without stressing the cuttings. Make the first application 6-7 days after sticking the cutting. Apply a second spray of growth retardant 4-5 days later, if required.