Moving Plants Inside in Winter
Temperatures of 50 °F or lower can damage many tropical plants via “chilling injury.” It is a good idea to move your houseplants inside when outside and inside temperatures are about the same. Plants need to readjust to life indoors before the heat is turned on. Before taking them inside, however, it is important to get rid of pests on the plant or in the soil. This is especially important for those plants that have been sitting on the ground.
Inspect the plants carefully. Take them out of their pots to see if anything has crawled in through the drainage holes. Wash the leaves and stems with the hose. Allow them time to dry, and spray the entire plant (upper and lower surfaces of leaves), soil and pot with an insecticidal soap. This soap is safe for people and pets. Leave plants outside for several days. Reapply insecticidal soap and take plants indoors two to three days later.
Some plants tend to hold the soap solution on their leaf surfaces. This may cause burning. Before using an insecticidal soap, check the label to see if the plant is listed. If not, test a small area on your plant for sensitivity. It may take seven to 10 days for symptoms to appear.
Over a period of about a week, gradually reduce light levels by moving plants from sun to light shade to heavy shade, and finally indoors. When you move plants indoors, make sure the light conditions are as close as possible to those out-doors. Once indoors, the plant may develop leaf yellowing or drop as it adjusts to lower light.
Moving Plants Outside in Spring
Most plants, with the exception of those with fuzzy leaves (e.g., African violet), benefit from a summer outdoors. Move them outside after frost, which is about early April in the Coastal Plains and mid-April in the Upstate (take them in if you have an unexpectedly cold night).
Gradually expose them to sunlight by placing them in deep shade under a tree for a few days and gradually moving them into brighter sunlight. Plants moved immediately into direct sunlight will burn and can become severely damaged.
Most succulents and cacti tolerate full sun, while other flowering plants like dappled light. Place foliage plants in heavy to light shade, depending on their needs. Try to place them out of drying winds, and in a spot where they will receive rain.
Plants grow more rapidly outdoors than indoors; therefore, they require more frequent fertilization and watering outdoors. In the heat of summer it may be necessary to water once or twice daily, especially when rainfall is not adequate.
Excerpted from the South Carolina Master Gardener Training Manual, EC 678.