COLUMBIA – When nighttime temperatures edge toward the frost mark, the time has come to prepare your plants for the trek indoors.
If indoor space is limited you will have to decide which plants to overwinter and which to discard, said David Trinklein, a University of Missouri Extension horticulturist.
“In most cases it is best to discard your annuals and purchase new plants next year,” he said.
Canna and elephant ear are exceptions and fairly easy to overwinter. After the first frost, dig them up and cut back the tops. Do not divide the rhizomes, as the fresh cutting may allow microbes to cause rot through the winter. Store the rhizomes in peat, vermiculite or sand in a cool, dry location with temperatures no lower than 40 degrees.
Tuberous begonias and caladium are also easy to store over the winter. If tuberous begonias were grown in containers, you can bring them in for winter enjoyment as houseplants.
If they are planted in the ground, dig up the tubers carefully after the first light frost and remove the top growth. Leave the soil and roots around the bulb intact and place the bulbs in a cool, dry area for two to three weeks. Then remove the soil and remaining roots, which should be shriveled by this time, and pack the bulbs in peat, sand or vermiculite to prevent moisture loss.
Gladiolus also needs to be dug and stored at temperatures above freezing for the winter months. Gladiolus develops from a corm, which is an underground stem. When the foliage is yellowed, these corms can be dug from the soil and the foliage removed. Let the corms dry for a week before placing them into old onion sacks or nylon stockings, where they can be stored in a dry location at about 50 degrees until time for planting.
Hibiscuses are ideal as houseplants. They will bloom throughout the winter if kept in a sunny window.
Before you bring plants indoors, carefully inspect them for insects that will proliferate in the warm, dry indoor conditions. Isolate the plants from any indoor houseplants for about two weeks to ensure they don’t contaminate the other plants.
