Some Houseplants Like it Cool
A few days back, I suggested it was time to bring any houseplants you’d put outdoors for the summer back indoors, but there are a few exceptions.
There is a small minority of houseplants that are not truly tropical in origin, but rather subtropical. In other words, in their original environment they experience cool temperatures part of the year, but not frost. These plants, unlike most houseplants, will prefer to spend the autumn outdoors and can tolerate temperatures as low as 33˚F (1˚C). Bring them only when frost is announced. Even when you do bring them indoors, if possible keep them in a cool place (below 60˚F/15˚C) all winter. In this category you’ll find the Indian azalea (Rhododendron simsii), some orchids (especially Cymbidium cvs), the Christmas cactus (Schlumbergera cvs), most other cacti and the lily of the Nile (Agapanthus).