I grow African Violets under lights year-round on two four foot wide stands each with 3 shelves. The room they normally ‘live’ in gets too cold during the winter so I moved them into the family room for the season. Even so, my hygrometer (measures temperature and humidity) still shows that the room can dip to 64 degrees at night at times. That’s really a bit colder than they like but they are still hanging in there. And I love to see their cute faces. Enjoy!