Some tropical plants, like cannas and banana trees, can be overwintered in a dormant state in a cool, dark place inside. Many others, however, should be treated as houseplants. Unless you live in a large house with walls of windows, you will have to decide which plants will move inside for the winter and which ones will end up in the compost bin.
Start by checking plants for insect infestations. Unless they are favorites, infested plants should be discarded. Treat prized plants and recheck them. It may take more than one application to get rid of pests completely. Don’t bring them inside until they are pest-free.
Next, assess the amount of light available inside. Plants that need bright light will decline quickly indoors if it is not available. Ficus, palms, crotons, agapanthus, ferns and many other plants will be happy in south-facing windows.
Expect some leaf drop when a ficus is brought indoors. They require less water in winter but need misting every couple days. Palms may respond to a move indoors with a few yellowing leaves. Let their soil dry before watering.
Crotons need bright light to retain their vivid foliage colors. They prefer moist, but never soggy, soil. Fertilize plants every couple weeks with a diluted houseplant fertilizer. Don’t fertilize agapanthus once inside for the winter, and let the soil dry before watering. Remove yellowing leaves as they appear.
Ferns enjoy a winter vacation indoors in bright light and high humidity. Let the soil almost dry before watering, but mist them every day.
Bring tropical plants inside well before the first frost. There tends to be a wide range of temperatures in fall, and big sways in temperatures are hard on plants. It is better to err on the side of bringing them in too early than too late.
Spray plants with a strong spray of water from the hose to wash away any insects trying to hitch a ride inside. If you notice any pests, treat before bringing them inside.
Provide the humid environment most tropical plants prefer. Mist regularly or set plants on saucers filled with pebbles. The pebbles lift pots out of the water while excess water in saucers evaporates, adding humidity to the air around plants. Grouping plants together also creates a more humid situation.
Without wind and rain to clean the foliage, wipe the dust from leaves periodically with a damp cloth.
• Diana Stoll is a University of Illinois Extension Kane County master gardener. Email the extension office at email@example.com for more information.