Neglect with respect: Caring for houseplants in the winter

“Extension on the Go” podcast by Debbie Johnson. Episode 160: Caring for Plants in the Winter

COLUMBIA, Mo. – Winter is probably the most challenging time of year to keep houseplants looking healthy and attractive.

Potted plants kind of doze in the winter because there’s less light and the air is very dry.

“Houseplants do little, if any, growing during the winter. They simply maintain themselves. That said, we don’t really need to be fertilizing plants such as this or watering them as often,” said David Trinklein, horticulture specialist for University of Missouri Extension.

Lack of adequate humidity in our homes is a real struggle for houseplants because many of them were tropical plants in a former life.

“Tropical rainforests receive a lot of moisture and the humidity is high. The average home in the dead of winter has a lower relative humidity than the Sahara desert,” Trinklein said.

To compensate for the low humidity, many people will mist their plants. But it probably does more for the person misting the plant than it does for the plant, Trinklein said.

The benefit of misting plants by hand lasts, at best, about 20 minutes, he said. Which means to make any difference in the relative humidity for the plant, you would need to mist the plant every 20 minutes, around the clock.

“It’s much easier to have some sort of humidifier put on your furnace or a cool-mist humidifier in your room,” he said.

The slow winter growth makes it a perfect time for houseplant care and maintenance.

“This is a good time to repot any houseplants with roots coming out of the drainage holes,” said Jennifer Schutter, horticulture specialist for University of Missouri Extension.

Choose a pot one size larger than the current pot, remove the plant, prune off any roots that need trimming and repot it in fresh potting soil, she said.

When transplanting houseplants to a new pot, be careful not to compress the new growing medium too tightly around the roots.

“A lot of people have heard that you want good contact between the new growing medium and the roots that exist in the original root ball,” Trinklein said. “The result is they tend to pack the new medium into the pot too tightly. That can hurt the root system.”

You should place plants that need lots of light in the sunniest spot in the home.

“A sunny windowsill is an ideal spot for sun-loving houseplants, but be sure the plants aren’t too close to the glass or they could be damaged by the cold,” Schutter said. “Also, since heating vents are often located underneath windows, those vents can cause the plants to dry out quickly.”

Keeping beautiful, healthy houseplants can be a real challenge if your thumb isn’t green. Don’t be discouraged; there are plants that can take neglect and keep going.

“The quintessential hard-to-kill plant would be Aspidistra elatior – cast iron plant. It’s recommended that if you can’t grow the cast iron plant, you should give up,” Trinklein said. “Variegated Chinese evergreen is very durable in the average home, as is Sansevieria – snake plant.”

For more information, the MU Extension publication “Caring for Houseplants” (G6510) is available for free download at http://extension.missouri.edu/p/G6510.