By Laura Pottorff, Colorado State University Cooperative Extension agent, horticulture and plant pathology
If your houseplants look a little sickly, don't fret. They likely just have the season change blahs.
Their unsightly appearance probably stems from a number of different conditions all working together over the change in season.
Houseplants are tropical plants. They prefer a growing environment of high humidity and warm, non-fluctuating temperatures. They also prefer even soil moisture. These tropical plants let us know when they're not getting the respect they deserve! Their leaf tips can turn brown, they can develop leaf spots and sometimes their leaves turn yellow.
Here are some conditions that might lead to an unhealthy appearing houseplant along with some suggestions for good plant care.
Dry winter months: During colder months, our home heating systems fluctuate on and off, circulating dry, warm air throughout the house. If plants are located near heating vents, they can develop leaf spots and brown tips. Misting of plants may help alleviate this condition. A better, but more costly solution for next winter, is to put many houseplants together on a tray filled with gravel. Fill the tray with water. This tactic provides the humidity they are looking for.
Fluctuating temperatures: If your houseplants are located near a window or an outside door, the surrounding temperature will fall sharply as the door opens and when the heat cycles off. If this is your plant's problem, consider moving it to another location or experiment to find a plant that is adapted to this location.
Un-even soil moisture: Tropical plants like to have their roots in soil that is evenly moist -- not too dry nor too wet. This often is a hard balance to keep. Dry leaf tips and spots will develop when we water once or twice a week "whether the plant needs it or not." When you water a plant under this scenario, you might be watering it when it's too wet. But, by the time you water next week, it may be too dry.
A better approach is to feel the soil before watering. Stick your finger a couple of inches into the soil and feel how wet or dry it actually is. You may have to check the soil every couple of days until you become accustomed to your plants. Be sure to check the soil diligently during a season change. A plant often will use water differently in winter than in summer.
Why do we see these symptoms develop so late in the winter season or sometimes not until early Spring? Because plants are slow to show symptoms. It takes a couple of months worth of dry, warm air or fluctuating temperatures before a typical houseplant will let you know it is unhappy. A better understanding of the conditions needed by a particular houseplant will lead to better plant health. For more information about houseplants and their care, contact your local Cooperative Extension Office.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010