Released: November 18, 2003

Winter Brings New List of Houseplant Needs

MANHATTAN, Kan. – Houseplants know when fall and winter arrive. Their needs change in line.

“Their growth slows down, due to less sunlight, so they don’t require as much water or fertilizer. At the same time, they start needing protection from both cold and hot drafts. Plus, given the seasons’ shorter days and low indoor humidity, they often benefit from help with those problems, too,” said Ward Upham, horticulturist with Kansas State University Research and Extension.

Upham said the “winter rules” for good houseplant care are:

* Water by touch, not by calendar. Irrigate only when the top inch of soil is dry. Provide enough water that some flows out the bottom of the pot, helping wash away the salts that build up in potting soil.

“Watering too often fills the air spaces in soil. Plants can become oxygen-starved,” he warned.

* Feed less. Flowering houseplants should get one-half the amount recommended on the fertilizer container. Foliage plants only need one-quarter as much food.

“During winter, a summertime fertilization program produces leggy, weak plants,” Upham said. “In fact, you may not want to fertilize at all during mid-winter, December-January, if the plants have no new growth.”

* Don’t place plants where they’ll be in contact with cold windows or on the receiving end of drafts from either heating vents or doors to the outside.

* If possible, move plants into the brightest indirect light available – probably near a window with a southern or eastern exposure.

“Many houseplants are natives of the jungle floor. They don’t need as much direct sunlight as High Plains garden plants do. Compared to the Plains, however, jungles provide long days and bright light – even in winter. So, when winter comes, we just have to do the best we can at duplicating that,” he said.

* If possible, keep the humidity up. In homes without a humidifier, plant owners can try placing their indoor pots on a water-filled tray of pebbles.

“In the High Plains, winter is one of the driest seasons of the year. Even our snow doesn’t often yield much actual moisture,” Upham said. “Add to that the air-drying effect of forced-air heating systems, and you can see why plants and people both can benefit if we raise the indoor humidity level a bit.”

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Kathleen Ward, Communications Specialist
kward@oznet.ksu.edu
K-State Research& Extension News