When you bring houseplants indoors before temperatures get too cold, be sure to leave pest problems out in the cold.

A rule of thumb is to bring plants in before night temperatures drop below 50 degrees Fahrenheit to allow plants to adjust to warmer indoor temperatures.

It’s a good idea to inspect plants for pest problems several weeks before you plan to bring them inside. This precaution gives you ample time to take care of any insect or disease problems. Look underneath the leaves for signs of aphids or the webbing of spider mites.

You usually can control small infestations of common insects, limited to a few plants, without using insecticides. For example, spray plants with water to wash off mites or use a swab dipped in rubbing alcohol to remove light infestations of aphids, mealybugs and scale. To eliminate heavy infestations, use a soft brush or cloth dampened with insecticidal soap.

If you decide to use a conventional insecticide on heavy infestations, always read and follow the manufacturer’s label instructions.

Insects can cause serious problems on plants inside during the winter, because the natural predators that help control these pests outside are not in your home. So, separate the plants you’ve just brought in from others for several weeks to ensure the newcomers don’t have insects that might travel to the other plants. Regularly inspect all plants to control inconspicuous pests you might not notice until a serious problem develops.

To combat foliar diseases, indicated by yellow, black or brown spots on leaves, remove and destroy the affected leaves, leave ample space between plants, avoid wetting foliage and move plants to a less humid area.

Root and stem rot diseases usually occur under extremely wet soil conditions so provide good drainage and avoid over-watering plants.

Once you bring plants inside, provide a favorable growing environment including light, humidity and fertility. And remember, most plants don’t like to be in a draft. Optimum conditions reduce the chance of disease problems. Some symptoms are leaf edge and tip death, leaf drop, yellow leaves and spindly growth.

For more information on plant pest control and other gardening topics, go to the Hardin County Cooperative Extension Service at 111 Opportunity Way in Elizabethtown, hardin.ca.uky.edu, call us at 270-765-4121 or Amy.Aldenderfer@uky.edu.