Houseplants, winter watering, and humidity

Posted by

Gardeners grow their houseplants all summer to get them healthy only to see them slowly decline all winter with the hope they are alive come spring. Late fall through December bring some of the lowest light levels into our homes, really limiting the growth of all of our houseplants. Come January, and forward, the light levels begin to improve, and our days of light are longer. But how does all this affect watering?

Keep watering down

Nearly all of our houseplants are “coasting” all winter long. They are not actively growing so they are not able to use water the way they used to and why we need to change our watering practices during the winter months. (Pro tip: when bringing in houseplants inside after summer, try to do so while they are on the dry side to acclimate to the new indoor surroundings.)

As for winter watering, here are some points to remember:

  • You will be watering less often.
  • Soilless media will dry out quicker than the older soils or garden dirt.
  • Older houseplants may have circling roots preventing drainage.
  • If you can use the same soil media in all the houseplants, watering becomes more manageable.
  • It is better to keep soils on the dry side, but plants should never wilt.
  • Plants in a southern or western exposure window dry out before east and north facing windows.
  • It is common to see older, damaged leaves yellow and fall.
  • Do not give plant food while the houseplants are inactive.

Keep humidity up

Houseplants will benefit from higher humidity levels that are present in most homes during the winter. One way is to group them together for the winter where they get to share the humidity around them. Another way is to place them on a bed of sand or fish tank gravel or pea gravel using a tray. When you do get to water them the excess stays in the sand, gravel, or pea gravel and evaporates into the air, providing the humidity. If you notice those materials are dry, go ahead and provide additional water in between the times you water your houseplants.

Just like the reminder during the holiday season for the fresh holiday tree, if you can turn off or redirect the hot dry air from the heater vents the happier the houseplants will be.

About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.