Prepare Plants Before Moving Them Indoors - U of I Extension

News Release

Prepare Plants Before Moving Them Indoors

This article was originally published on September 14, 2010 and expired on October 15, 2010. It is provided here for archival purposes and may contain dated information.

Plants that were taken outside during the spring need to be prepared to return indoors, said a University of Illinois Extension plant pathology specialist.

"If plants are brought in without any re-adaptation, the leaves will yellow and fall off just like they did when the plants were taken outside in the spring without proper hardening off," James Schuster said. "Proper preparation will take at least two weeks to minimize foliage defoliation. Plants should first be checked for any insect damage and actual insects, including their eggs."

Examine the undersides of the leaves as well as where the leaf petioles attach to the stem. Using a cotton swab and rubbing alcohol, remove any insects and eggs. In some cases, an insecticide or organic pesticide may be necessary.

"This insecticide must come in contact with the insect to kill it since there are no residual activities for prolonged control," Schuster said. "Therefore many repeat applications may be necessary. But be careful—this product may injure some plants, especially succulents and cacti, when used as a soil drench for mealy bugs."

Insects and their eggs are often in the soil. On very porous soils, more mealy bugs will feed on plant roots than on the upper part of the plant. For longer control, an inorganic insecticide may be more appropriate.

"Follow all label directions and precautions on both organic and inorganic insecticides," Schuster said. "Instead of using an insecticide, you can remove old soil, rinse the roots, and repot the plant with fresh soil when it is finally brought into the house. However, both insecticide use and repotting can cause serious stress to the plant."

Diseases are a little more difficult to control as there are no curative fungicides for most diseases. Therefore, they need to be prevented. Powdery mildew can be a serious indoor disease on the plants you had outside. It often causes severe defoliation weeks after the plant was brought in. You may or may not see a white powdery growth on the foliage. Begin to use a fungicide several weeks before the plant is brought inside. Fungicide treatments should not be used on plants once they are indoors.

"Plants need to be slowly reconditioned to indoor growing conditions," Schuster said. "Start by bringing the plant into the house for an hour or two and then putting it back outside. Each day add several more hours to its inside time.

"While doing this routine, keep the plant away from those that have been inside all summer to prevent the spread of insects and disease. After two or three weeks, the plant should be ready to stay inside. Do not wait for frost to start preparing your plants for indoor life."

Source: James Schuster, Horticulturist and Plant Pathologist (Retired),

Pull date: October 15, 2010