Many gardeners like to bring their houseplants out onto a deck, balcony, or patio in summer for a little rejuvenation. It's good for houseplants to get some fresh air, bright indirect light, and natural watering in summer.
But most of these houseplants are subtropical in origin, meaning once the temperatures dip into the 40s at night, it's time to move them back indoors. Cold night temperatures can cause leaf damage.
But it's not as simple as just bringing the houseplants back inside. They do best with a transition period from outdoors to indoors. Start by moving the houseplants into a shady location. This will help them adapt to the lower light levels indoors. You can also bring them indoors on chilly nights, moving them back outside during the day. Then start bringing them in for half a day during the day. After about five days, bring them in for good.
During this transition period, look for insects. Aphids, white flies, scale, and mealybugs are just some of the insects that will hitch a ride indoors and infest your houseplants. Check the underside of leaves and on stems for these pests and spray insecticidal soap, Neem oil, or horticultural oil to control them. You may want to do a couple sprayings before bringing plants in for winter to kill hatching eggs.
Once indoors, quarantine the plants away from other houseplants for a few weeks and check for more insects. Reduce watering, stop fertilizing, and don't be surprised if some leaves drop due to the low light levels indoors. Your goal is to get them to survive the winter.