Calathea plants are popular houseplants, known for their striking foliage and vibrant patterns. Native to the understory of rainforests in Central and South America, their unique appearance makes them a favored choice for indoor spaces.
Calathea Care Essentials
Calathea plants thrive with consistent attention to their environmental needs. Providing the right conditions supports their lush growth and vibrant leaf patterns.
Light
Calatheas flourish in bright, indirect light, mimicking their natural rainforest habitat. Direct sunlight can scorch their delicate leaves, causing patterns to fade and leaves to brown. Positioning them a few feet from an east, south, or west-facing window, or behind sheer curtains, provides ideal illumination.
Watering
These plants prefer consistently moist soil, but they are sensitive to overwatering, which can lead to root rot. Water when the top inch or two of the potting mix feels dry to the touch. Calatheas are also sensitive to minerals found in tap water, such as chlorine and fluoride, causing leaf discoloration; using filtered, distilled, or rainwater is recommended.
Humidity
High humidity is an important factor for healthy Calatheas, as they originate from humid tropical environments. They thrive when humidity levels are consistently above 50%, ideally between 60% and 70%. Methods to increase humidity include placing the plant on a pebble tray with water, using a room humidifier, or grouping several plants together to create a humid microclimate.
Soil
An ideal potting mix for Calatheas should be well-draining yet capable of retaining adequate moisture. A lightweight, rich organic medium, a blend containing peat moss, coco coir, perlite, and aged bark, provides balance. This type of mix ensures good aeration for the roots while preventing waterlogging.
Fertilizing
Calatheas do not require heavy fertilization. During their active growing season in spring and summer, a diluted, balanced liquid houseplant fertilizer can be applied every two to four weeks. Reducing or stopping fertilization during fall and winter, when the plant’s growth slows, prevents nutrient buildup and potential root damage.
Temperature
Maintaining a stable temperature range is important for Calathea health. They prefer temperatures between 65°F and 85°F (18°C and 30°C) and are sensitive to cold drafts. Avoiding placement near fluctuating temperatures, such as those from open windows, doors, or heating/cooling vents, helps prevent stress and potential leaf damage.
Common Calathea Problems
Despite proper care, Calatheas can sometimes exhibit signs of distress related to their environmental needs. Recognizing these issues helps in prompt rectification, ensuring the plant’s continued health.
Browning or Crispy Leaves
Browning or crispy leaf edges on Calatheas are a common indicator of insufficient humidity or inconsistent watering. Low humidity causes leaves to dry out, leading to crispy margins. This issue can also stem from underwatering, where the plant does not receive enough moisture, or from mineral buildup in the soil due to tap water.
Curling Leaves
Calathea leaves curling inwards signal that the plant is not receiving enough water or is experiencing low humidity. When the plant is dehydrated, either from dry soil or dry air, its leaves curl to conserve moisture and reduce transpiration. Cold conditions or excessive direct light can also prompt leaves to curl as a protective mechanism.
Pests
Calatheas can be susceptible to common houseplant pests, particularly spider mites, mealybugs, and aphids. Spider mites, often appearing in dry conditions, create fine webbing and cause tiny yellow spots as they feed on sap. Mealybugs manifest as small, white, cottony masses on stems and leaves, while aphids are small, pear-shaped insects that cluster on new growth.
Inspecting the undersides of leaves regularly helps in early detection. Treatment involves isolating the affected plant, wiping away visible pests with a damp cloth or alcohol-dipped cotton swab, and applying insecticidal soap or neem oil to all leaf surfaces. Increasing humidity can also deter spider mites, which prefer drier environments.
Popular Calathea Varieties
The Calathea genus includes a wide array of species, each with distinct leaf patterns and aesthetic appeal, making them highly sought after by indoor plant enthusiasts.
Here are some popular varieties:
Calathea Orbifolia is known for its large, rounded leaves adorned with striking silvery-green stripes radiating from the center.
Calathea Medallion, also known as Goeppertia roseopicta ‘Medallion’, features broad, oval leaves with a dark green border and a vibrant, lighter green or silvery pattern in the center, complemented by purple undersides.
The Calathea Lancifolia, commonly called the Rattlesnake Plant, displays long, lance-shaped leaves with wavy edges, marked by dark green patterns resembling rattlesnake scales and a deep purple underside.
Calathea Zebrina has velvety, dark green leaves with lighter green stripes.
Calathea White Fusion is known for its marbled patterns of white, green, and lavender.
Unique Calathea Characteristics
Beyond their captivating patterns, Calathea plants possess a unique behavior known as nyctinasty, often leading to their common moniker, “prayer plants.” This characteristic involves the rhythmic movement of their leaves throughout the day and night.
The leaves flatten out during daylight hours to maximize light absorption for photosynthesis. As evening approaches, the leaves fold upwards, resembling hands clasped in prayer. This movement is controlled by specialized joints called pulvini, located at the base of each leaf. These pulvini respond to changes in light intensity by altering water pressure within their cells, causing the leaves to open and close in accordance with a circadian rhythm. This natural adaptation helps the plant conserve moisture and protect its foliage during nighttime.