Moving indoor/outdoor plants back indoors is in full swing in early September. Many gardeners have a full patio of container plants at this point in the season, some of which are well-suited to bring back indoors for winter enjoyment. The key to success is doing it gradually.
Start by moving the pots that have a good chance of success indoors into the shade. A big shade tree is great, as it allows them to grow in lowered sunlight volume and good airflow. Leave them there until the nighttime temperatures dip into the low 40’s, usually around the end of September. While they are experiencing lowered light levels, their chloroplasts (internal organs that photosynthesize) will begin to grow more horizontal, and build capacity for absorbing light that was not needed outdoors, but will be important indoors.
In the next few weeks, take the time to pick out new pots for them, especially for mature specimens. One of the biggest “houseplant killers” is the pot itself. It’s essential that it drain well, via several small holes in the bottom. If you don’t like the looks of clay or plastic, you can utilize double potting, where ordinary pots are placed inside highly attractive ones. This will allow for proper watering and shedding of excess water. A good rule of thumb is to water until about 10% of the applied water drains out the bottom of the pot. Alternatively, you could drill holes in the bottom of any pot and use a drip tray to collect the water that drains out.
Once new pots have been chosen, “harvest” plants that grow well indoors in a Midwest winter such as geraniums, hibiscus, pothos, peperomia, croton and begonia, gently removing them from their outdoor pot and placing them in their new one. Before smashing in the roots, take a little time to loosen ones that are circling or overgrown. This will likely remove any decayed roots or soil pests as well.
Finally, check them for pests – spider mites, aphids, whiteflies, mealy bugs, fungus gnats – that may be lurking on the undersides of leaves and on stems. Carefully remove any tag-alongs and discard them. If they are stubborn, apply an insecticidal soap or horticultural oil according to label directions.
