LSU AgCenter Horticulturist
BATON ROUGE — Louisiana gardeners often use containers of tender tropical plants on decks, patios and porches and in courtyards to provide color and beauty through the summer. These plants thrive in outdoor conditions. But because they cannot withstand freezing temperatures, they must be protected during winter. Generally, this means bringing them indoors.
Before bringing tropical plants inside, decide which ones you really want to protect. A few might be readily available and are relatively inexpensive to buy. It might not be worth the trouble to bring inside plants that are easily replaced.
For those that will be brought inside, however, look through the house and decide where to put them. Remember, they must be located in or near windows or glass doors so that they get plenty of light.
One of the most difficult problems these plants must deal with when they’re brought inside is the sudden reduction in the amount of light they are accustomed to receiving. Plants use light as their source of energy to create the food they need to live and grow. When their light is suddenly and greatly reduced, it’s as if they were put on a “starvation diet.”
It’s a good idea to move outdoor tropicals to a shaded outdoor location a couple of weeks before moving them indoors. Acclimating them to lower light conditions helps them adjust to the reduced light they’ll have available when inside. The better the plants acclimate and the more light provided for them indoors, the less leaf drop will occur.
Houseplants that spent the summer outside should also be groomed before bring them in. This will help plants look their best, and will be less likely bring pests inside.
—Clean outside of containers using a damp cloth or a brush and a mild solution of dishwashing liquid and water, if needed. Do not get this solution in the soil.
—Remove dust and debris from the foliage and where leaves join the stems. Hose down the plants and wipe the foliage clean with a soft damp cloth.
—Remove all dead or yellow foliage, old flower stalks and dead or injured branches and stems.
—Do not repot a plant immediately prior to moving it indoors. Repotting should be done four to six weeks before bringing a plant inside. At this point, just wait until spring if it needs repotting.
Watering and fertilizing
Once they are moved inside for the winter, houseplants will need to be watered less often. How much less water they need is something that will have to determine. Feel the soil regularly with a finger and water when the soil feels dry but before the plants wilt. Remember, it is better to water less often than to water too often and cause root rot. Cactuses and succulents are particularly vulnerable to over watering, so be especially careful about not watering them too often.
During winter, water coming out of indoor faucets can be decidedly chilly. Tropical plants do not appreciate being watered with cold water, and in some cases it can even cause damage, such as spots on African violet leaves. When filling up the watering can at the tap, mix hot water with cold until the water temperature feels tepid or barely warm.
Generally, plants brought in for the winter will not need to be fertilized at this time of year. They will usually slow down or stop any new growth and enter a dormant or semi-dormant state. Indoor plants that show active, vigorous growth during winter could be fertilized.
Do a good, thorough job of pest control before bringing houseplants inside. Thoroughly clean all snails and slugs from the bottoms of pots and dispose of them. Spray plants infested with aphids, spider mites, white flies, scale or thrips with a light horticultural oil spray. Spray thoroughly to coat all surfaces of the plant, including under the leaves. This also leaves a nice shine on the foliage.
Gardeners sometimes find that ants have taken up residence in the soil of a container. Kill them by drenching the soil with a solution of permethrin mixed according to label directions.