BY RICHARD JAURON, GREG WALLACE
AMES, Iowa – Houseplants provide much-needed beauty and color to a home during winter’s cold blast, but they do require some special care to keep them vibrant during freezing temperatures, even inside. What are optimal suggestions for houseplants in winter?
Iowa State University Extension and Outreach horticulturists can help answer your questions about houseplants and how to handle them during the winter. To have additional questions answered, contact the ISU Hortline at 515-294-3108 or hortline@iastate.edu.
How often should houseplants be watered in winter?
In general, houseplants require less frequent watering during the winter months than in spring and summer. Watering frequency depends upon the plant species, composition of the potting mix, environmental conditions (temperature, light and humidity), and other factors. When watering houseplants, continue to apply water until water begins to flow out the bottoms of the pots. Discard the excess water.
Should houseplants be fertilized in winter?
Fertilization is generally not necessary during the winter months as most houseplants are not growing during this time. Indoor gardeners should fertilize their houseplants on a regular basis in spring and summer when plants are actively growing.
What are suitable temperatures for houseplants in winter?
Most houseplants prefer daytime temperatures of 65 to 75 degrees Fahrenheit and nighttime temperatures of 60 to 65 degrees Fahrenheit. Temperatures below 50 degrees Fahrenheit or rapid temperature fluctuations may harm some plants. Keep houseplants away from cold drafts, radiators and hot air vents. Also make sure houseplants don’t touch cold windows.
How can I raise the relative humidity indoors for my houseplants during the winter months?
Many houseplants prefer a relative humidity of 40 to 50 percent. Unfortunately, the humidity level in many homes during the winter months may be only 10 to 20 percent. Humidifiers are an excellent way to increase the relative humidity in the home. Simple cultural practices also can increase the relative humidity around houseplants. Grouping plants together is an easy way to raise the humidity level. The water evaporating from the potting soil, plus water lost through the plant foliage, will increase the relative humidity in the vicinity of the houseplants.
Another method is to place houseplants on trays (saucers) filled with pea gravel or pebbles. Add water to the trays, but keep the bottoms of the pots above the water level. The evaporation of water from the trays increases the relative humidity around the plants.
