When temperatures dip, spend indoor time with your houseplants

During the winter, most houseplants are not in an active growth phase because of short day lengths, reduced humidity and lower temperatures, unless you are growing them in a greenhouse. Generally, houseplants require less water and much less, if any, fertilizer because their growth slows down during the winter.

The plant species will also affect the required frequency of watering but most will prefer watering when the medium is barely moist to the touch or almost dry. Ferns will prefer to be kept more evenly moist while succulents will prefer to dry out more between watering. Water houseplants thoroughly when you do water them. Water should freely drain out of the bottoms of the pots. If the excess water drains into a saucer, discard the water and replace the saucer beneath the pot.

Most houseplants will perform well with daytime temperatures of 65 to 75 degrees and night temperatures of 60 to 65 degrees in winter. Temperatures below 50 degrees or rapid temperature fluctuations may damage some plants. Keep houseplants away from cold drafts, radiators and hot air vents. Also, make sure houseplant foliage doesn't touch cold windows.

House plants with large leaves and smooth foliage, such as philodendrons, dracaenas and rubber plants, can benefit if their leaves are washed at intervals to remove dust and grime. Cleaning houseplants improves their appearance, stimulates growth and may help control insects and mites. Large, firm-leafed plants may be cleaned with a soft sponge or cloth and tepid water. Another method is to spray off the leaves in the shower.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.