Cool Temps for Parvis-How Long?

[Chlorophile]

I have emersonii, micranthum, malipoense, and armeniacum that are finally BS. The room they are gets cooler at night by a degree or two but not much more. I’ve been putting them on the window sill and opening the window a crack to give them a cool nighttime drop. My question is how long do I do this? Do I wait until I get buds or do I just do it until the weather starts to warm up in Spring?

[signin1234]

I wouldn't do this at all with P. malipoense. That species likes it warm and wet. And if it hasn't spiked by now, it's probably not going to this season.