COLUMBIA, Mo. – When the outdoor growing season wraps up, moving your potted tropical plants indoors upgrades mere winter shelter into a lush jungle paradise, said University of Missouri Extension horticulturist David Trinklein.
Tropical container plants have surged in popularity in recent years. They typically require a larger upfront investment than annuals, but overwintering them lets gardeners enjoy those plants for several years rather than a single season.
Move your tropical plants inside well before the first frost. Many tropical plants suffer from chill injury when night temperatures consistently fall below 45 F.
Before moving plants indoors, thoroughly inspect them for pests. Mites, a common plant pest, are difficult to detect because they are so small. Eliminate mites by washing leaves thoroughly with a mild detergent or spray the plant with a pesticide labeled for use on mites indoors.
Place smaller plants in a sunny window. They should bloom periodically throughout the winter. Use other techniques if you have larger plants or lack adequate indoor lighting.
Put woody tropical container plants in a cool location and let their leaves drop. An unheated garage that maintains a temperature of 45-50 F is an ideal location. The lower temperatures cause the plant to go dormant for the winter.
Dormant plants have no leaves and do not require much water. Keep the root system “barely moist.” Don’t let the roots dry out during dormancy.
Hibiscus and bougainvillea are examples of species to overwinter by forcing them into dormancy. Both will initiate new leaves and growth the following spring when placed outdoors after the danger of frost has passed.
You can winter other tropical plants by harvesting and safely storing the bulbs, tubers or corms they produce. Elephant ear is a good example. Its large leaves make it impractical to overwinter as a mature plant. Instead, dig its tuber after the first frost. Cure it for several days and put it in a moistened material such as peat moss. Store at 45-50 F.
For overwintering, the “500-pound gorilla in the room” has got to be a banana plant, Trinklein said. What do you do with a plant that has grown 6-8 feet high in one summer? Simple: Cut it back and move the “stump” into an area where temperatures average 45-50 F. Move it outside in spring after the danger of frost has passed.
In most cases, overwintering tropical plants not only saves money, it also results in larger, more impressive plants the following year, he said.