Sauk County Gardener: Winter houseplant care

Jeannie Manis

“Like people, plants respond to extra attention.” ~H. Peter Loewer

Over the holidays, I traveled to Florida to attend a bowl game. Although the bowl game was wonderful and the temps were fabulous (mid-80s), the highlight of the trip for me was our visits to two botanical gardens. All those blooming plants got me excited about gardening, but I think I’ll have to wait a bit – at least for gardening outdoors.

Now is great time to assess your houseplants and give them the extra care they need during the winter. Plants like the humidity to be around 50 percent, but the humidity in our homes can get quite low in the winter. Using a humidifier can help remedy this issue, plus it’s beneficial to you as well. We have a small humidifier that we have placed near our collection of houseplants in our south-facing windows. By grouping the plants together, it helps creates a microclimate that is a little more humid than the rest of house. If a humidifier is not an option for you, place your plants in a shallow saucer with small pebbles and then fill with about a half inch of water. The water will evaporate and add humidity to the air. Misting your plants won’t help raise the humidity, but it will help manage spider mites who like drier conditions.

In the winter, it’s harder for plants to get adequate light. Place your plants in either a south- or west-facing window to give them as much light as possible. Make sure they are not touching the glass. To help keep them growing straight, rotate them a quarter-turn every time you water.

Houseplants tend to need less water as growth slows down during the winter. In many cases, the top of the soil will feel dry but the soil near the bottom of the pot will be moist. Before watering, stick your finger in the soil to see how dry the soil really is or simply pick up the pot. If the pot feels light, then water the plant. You can also put the potted plant in a sink of room temperature water. After about 15 minutes, let the plant drain. One thing to keep in mind is plants that are near vents or in bright windows tend to dry out much quicker so you may need to water them more often.

Fertilizing in the winter typically isn’t needed as growth slows or the plant goes dormant. Wait until late winter/early spring for new growth and then start fertilizing as needed. The exception is flowering plants such as African violets and orchids.

Temperature is important to monitor as well. Plants tend to like the same temps that we do; daytime temps between 65 and 75 degrees F and cooler at night. However, African violets and orchids tend to like it a little warmer. Bonus - cooler night temps can help keep insect pests in check.

Finally, check your plants for any insects. Determine what they are first before treating. Give them a lukewarm shower once a month will not only help keep insects in check, but also help remove dust that hinders photosynthesis. Take this time to give your houseplants a little TLC – a little bit goes a long way in keeping your plants healthy.

Jeannie Manis is a Wisconsin-certified Sauk County Master Gardener volunteer. If you have any gardening questions, please contact the Extension Sauk County by emailing to or calling the University of Wisconsin Madison Division of Extension Sauk County office at 608-355-3250.