Calathea plants, often called “Prayer Plants,” are sought-after houseplants known for their dramatically patterned foliage and unique daily leaf movements. These tropical plants require high humidity levels to truly thrive indoors, leading to a reputation for being temperamental. Misting is a common practice used by owners to meet this need.
Calathea’s Need for High Moisture
The Calathea genus originates from the shaded, humid understory of Central and South American rainforests, where air moisture rarely drops below 60%. When moved indoors, especially with central heating or air conditioning, the air becomes significantly drier. This discrepancy is the root cause of most Calathea care challenges.
The plant communicates distress when the air is too dry, most commonly through the browning and crisping of leaf edges and tips. This occurs because the plant loses moisture faster than its roots can supply it, causing the delicate leaf tissue to dry out. Leaves may also curl inward to conserve internal moisture. A prolonged dry environment also makes the plant susceptible to pests like spider mites.
Misting Schedule and Proper Application
Misting a Calathea should be done consistently, often daily or even twice daily during peak dry periods like winter when heating is active. Consistency is important, as the goal is to provide a brief, localized spike in moisture around the foliage. However, misting alone provides only a temporary boost, as the water evaporates quickly, often within minutes.
When applying a mist, use distilled, filtered, or rainwater instead of tap water. Tap water contains mineral salts that can build up on the leaves, leaving white spots, and accumulate in the soil. Use a fine-mist spray bottle, targeting the air surrounding the plant and lightly coating the undersides of the leaves. Avoid soaking the leaves or the soil.
The best time of day to mist is in the morning. Misting earlier allows the water droplets to evaporate throughout the day under brighter conditions. Leaving water to sit on the leaves for extended periods, especially overnight, increases the risk of fungal or bacterial leaf spot diseases.
Alternative Methods for Increasing Humidity
Misting is a helpful supplemental practice, but it is not a sustainable, long-term solution for maintaining the required high humidity. For a Calathea to thrive, the ambient relative humidity should ideally be maintained between 50% and 70%. The most effective and reliable method to achieve this sustained level is by using a dedicated humidifier, which can be set to a specific percentage to ensure consistently moist air.
If a humidifier is not an option, creating a localized microclimate can significantly help. Placing the Calathea on a pebble tray is a simple method: fill a shallow tray with pebbles and add water just below the top of the stones, ensuring the pot does not sit directly in the water. As the water evaporates, it raises the humidity immediately around the plant.
Grouping several houseplants close together also increases the local humidity, as plants naturally release moisture into the air through transpiration. Placing a Calathea in a naturally humid room, such as a well-lit bathroom or kitchen, can also provide a beneficial environment.