Houseplants that spend warmer months outdoors benefit from increased light, humidity, and air circulation. Since most of these tropical species originate from climates without freezing temperatures, they must be moved inside before cold weather arrives. Low temperatures cause cell damage, which quickly leads to plant death. Proper preparation and a slow move prevent the environmental shock that often results in significant leaf drop and stress.
Determining the Right Time to Move Plants
The timing for the move is determined by nighttime temperatures, which indicate cold stress for tropical plants. Most common houseplants begin to suffer damage when temperatures drop below 50–55°F (10–13°C). It is safest to begin the transition when overnight temperatures are expected to fall into this range.
Waiting too long risks subjecting plants to a hard frost, which can kill foliage within hours. Bring the most sensitive species, like basil or begonia, inside first, followed by hardier varieties. You can also start acclimation by moving plants into a sheltered area, such as a covered porch or garage, for a few nights.
Inspecting and Eliminating Outdoor Pests
Before any plant moves inside, a comprehensive inspection for hitchhiking pests is mandatory to prevent an indoor infestation. Outdoor conditions foster insects like aphids, spider mites, mealybugs, and scale, which multiply rapidly indoors without natural predators. Thoroughly examine all surfaces, paying close attention to the undersides of leaves, stem joints, and the pot’s rim and drainage holes.
Physical removal is the first defense against visible pests. Use a strong spray of water to blast away aphids and spider mites, focusing on the undersides of leaves. For stubborn pests like scale or mealybugs, use a cotton swab dipped in rubbing alcohol to manually dislodge them.
After physical cleaning, treat the plant with insecticidal soap or neem oil, which are effective against soft-bodied insects. Insecticidal soap disrupts cell membranes upon contact. Neem oil works as both an insecticide and a fungicide, suffocating insects and disrupting their feeding.
Pests also hide in the potting mix, such as fungus gnat larvae or slugs. To address soil-borne threats, scrape off the top one to two inches of existing mix and replace it with fresh, sterile soil. Systemic granular insecticides can also be applied to the soil, making the foliage toxic to sap-sucking insects. Finally, clean the exterior of the pot with a brush and soapy water to remove any lingering eggs or larvae.
Adjusting Plants to Indoor Conditions
Once pest-free and inside, plants need a period of gradual adjustment to the change in environmental conditions. The dramatic reduction in light intensity can cause light shock, resulting in leaf yellowing and drop. Place newly moved plants in a quarantine area with bright, indirect light for two to four weeks, keeping them away from established houseplants.
To manage light shock, position plants in the brightest available indoor location, typically near a south or west-facing window. If natural light is limited during short winter days, use supplemental LED grow lights. This prevents the leggy, stretched growth that indicates inadequate light.
The plant’s care routine must be altered to match its slowed winter growth cycle. Since indoor humidity is lower and air circulation is reduced, water evaporation decreases significantly. Overwatering is the most common cause of decline, so only water when the top two inches of soil feel completely dry.
Indoor air is often dry due to central heating, stressing tropical plants that require higher humidity. Grouping plants closely together creates a microclimate with increased local humidity. Alternatively, place pots on shallow trays filled with pebbles and water, ensuring the pot base remains above the water level to prevent root rot.