Botanical name: Calathea spp
Calatheas are grown for their ornately patterned leaves. They are striking plants that will add a splash of color to any space. They make a spectacular focal point in any room. Calatheas are native to the tropical regions of America. Like the shady floors of tropical canopies, they prefer low to medium light. Too much direct sunlight can damage their fragile leaves resulting in sunburn and dullness in the color of leaves. They also require high humudity to mimic their natural habitat. They should be kept moist but not wet. Overwatering or underwatering can lead to brown dry leaves. Due to their need for high humidity, Calatheas do well in a terrarium and a bottle garden where the humidity can be quite high.
Popular varieties include Calathea mokayana commonly called Peacock Plant which is the showiest among the Calatheas. With 1ft long papery leaves borne on long stalks and the decorative tracery gives rise to one of its common names - Cathedral Windows. One unique member in the Calatheas group is the Calathea crocata which has quite plain foliage and it is popular for its display of erect orange-red flowers. Other Calathea plants are Calathea zebrina (Zebra plant), Calathea insignis (Rattlesnake plant), Calathea roseopicta, Calathea lubbersii, and Calathea ornata among many others.
Calatheas are closely related to the Marantas, Ctenanthe and Stromanthe. These groups of plants are sometimes commonly called Prayer Plants in reference to their curious characteristic of closing their leaves at night.
Calatheas prefer partial light as colors fade in bright light. Keep them away from direct sunlight as it can lead to sunburn on leaves. Learn how to ensure your plant receives the correct light in this guide on understanding light for houseplants.
Watering Calatheas requires keeping the soil moist at all times during the growing season. Reduce watering in the cold season. Use tepid water that is free of chlorine and flourides as Calatheas are sensitive to chemicals dissolved in water. Avoid waterlogging as it can lead to root-rot. To prevent fungal infestation, avoid wetting the foliage during watering or water from the bottom. Learn more on how to water houseplants.
Calatheas prefer average warmth with a minimum of 150C. Protect these plants from cold draughts and sudden changes in temperature.
Calatheas require high humidity. To raise humidity, surround the pot with wet moss or place the pot on a wet pebble tray. Calatheas can also be grown in a terrarium as the humidity in a terrarium is quite high. Clean the leaves by damp-wiping with a soft cloth to keep them clean and neat.
Feed Calatheas with a water-soluble balanced fertilizer once monthly through out the growing season. Withhold feeding in the cold season as growth is minimal so feeding at this time can lead to fertilizer. Learn more on feeding houseplants.
Repot Calatheas every 2 years at the beginning of the growing season. Use a pot with a drainage hole(s) and free-draining soil that is rich in organic matter. The plants do not like to sit in soggy soil so ensure the soil is free-draining and the pot has a drainage hole. Divide the plant at the time of repotting and use the splits to propagate new plants.
Pruning Calatheas is easy as it involves removal of dead and yellow foliage to maintain the plant neat and attractive.
Calatheas are propagated by division at the beginning of the growing season during repotting.
Propagation of Calatheas by division
Remove the plant from its pot and divide it into several sections. Pot the sections into individual pots containing moist free-draining soil. Cover the pots with clear polythene to create a greenhouse effect to maintain warm humid conditions which hasten establishment. Place in a warm shaded place until new growth has emerged. Gradually remove the polythene over a period of two weeks to acclimatize the plants. Then move the set up to a cool shaded place and maintain the soil moist until the plants are well established.
The cause of leaf drop in Calatheas is that the air is too dry. These plants are very sensitive to low air humidity. To raise humidity, surround the pot with damp moss or place it on a wet pebble tray. Calatheas can also be grown in a terrarium as the humidity in a terrarium is quite high.
The reasons for limp rotting stems in Calatheas are the air is too cool and the soil is too wet. At this point, the plant may be too far gone to be saved.
Direct sunlight on Calatheas is the cause of discolored and scorched leaves. Move the plant to a shaded spot or protect it from direct sunlight immediately to prevent its death.
Underwatering is the reason for curled, spotted and yellowing leaves in Calatheas. Calatheas require that the soil be kept moist at all times during the growing season. Do not le the soil dry out slightly between waterings during the growth period. Learn more on how to water houseplants.
The cause of brown and dry leaf-tips accompanied by stunted growth in Calatheas is Red Spider Mites infestation due to the air being too dry. Remove dead growth, mist the leaves regularly and set the pot on a wet pebble tray to raise humidity.
Calatheas are prone to Leaf Spot Disease due to the humid conditions which they prefer.
Calatheas are non-toxic to both humans and pets. They are safe to grow indoors. However, they should not be eaten.