By Maddy Rohr, K-State Research and Extension news service

Manhattan, KS — While temperatures drop outside as winter approaches, indoor plants still need care. Kansas State University horticulture expert Ward Upham said houseplants require less water and fertilizer during the shorter days.

Upham said this is because longer days offer more light, which produces fuel for growth. More growth requires more water and nutrients.

“When light is limited, the need for water and nutrients decreases dramatically and it becomes easy to overwater and over-fertilize during the winter months,” Upham said.

Overwatering and excess nutrients could damage the root system.

“Overwatering can suffocate roots by eliminating oxygen, and excess fertilizer can burn roots,” Upham said.

He suggests fertilizing houseplants with a quarter of the recommended amount in November and February, and not at all in December and January.

“It is never wise to water on a set schedule. Rather, allow the potting soil to tell you when watering is needed,” Upham said.

To measure moisture, insert a finger into the potting mix, about one-inch deep. Only water the plant if the potting mix is dry.

Upham and his colleagues in K-State’s Department of Horticulture and Natural Resources produce a weekly Horticulture Newsletter with tips for maintaining home landscapes and gardens. The newsletter is available to view online or can be delivered by email each week.

Interested persons can also send their garden and yard-related questions to Upham at wupham@ksu.edu, or contact your local K-State Research and Extension office.