Houseplants Require Special Care in Winter

By Gary Hall

Question: Why do houseplants need special care during winter months?

Answer: Houseplants are great companions: They provide needed oxygen, usually require less attention than a pet, don't say much and add a splash of color to their surroundings. You can even decorate them for Christmas. However, during this time of year they need special care due to colder temperatures, lower humidity and reduced sunlight. Because houseplants grow more slowly during the short days of winter, adjust the watering and fertilization schedules and consider moving the plants to a new location.

A. Watering is probably the most important activity in the care of houseplants. In winter, we usually need to resist the urge to water. Excess water fills air spaces within the soil resulting in roots that receive less oxygen than they need. This can drown the roots and encourage all kinds of diseases, and even swarms of fungus gnats.

Water by touch, not by calendar. If the soil is dry an inch deep, it's time to water. Be sure to add enough so that some water flows out the bottom of the pot. This will help flush out excess salts that tend to accumulate within the potting soil. But don't let the plant sit in excess water.

Q. Should I fertilize my houseplants during the winter?

A. Fertilization is a good idea but should be reduced in the winter. Apply half the recommended amount of fertilizer for flowering houseplants and one-fourth the amount for foliage houseplants. Too much fertilizer results in plants that become leggy and weak.

Q. What else should I know about keeping houseplants healthy this time of year?

A. Location is another important factor for houseplant health. Since day length is so short, consider moving them to areas of the room that receive more light, such as a south- or east-facing window. Keep your plants away from drafts created by doors or air being blown from heating ducts.

Relative humidity also tends to be low during the winter. If you do not have a humidifier, frequent misting of the plants or placing them on water-filled trays of pebbles can help raise the humidity.

Reprinted from the Saturday, December 13, 2003, Rocky Mountain News.

Gary Hall is a Colorado State University Cooperative Extension Horticulture agent in Custer County.