Calathea or zebra plants are tropicals widely grown by gardeners looking to add interest to their home. Because these plants evolved in the tropics, they cannot be grown outdoors in the UK during the winter but prosper in greenhouses, conservatories or as a houseplant. Give your calathea plant proper care to ensure it is able to contribute healthy, colourful leaves.
Calathea plants can be grown indoors or outdoors during the summer as long as they are not set in a place where they receive direct sunlight. Outdoor areas could include under trees, near taller ornamental plants or where an outdoor structure casts shade on the plant for part of the day. Indoor areas should be next to a window that has a sheer curtain. Wilted or discoloured calathea leaves can be an indication that your plant is getting the wrong kind of light.
Gardeners should bring their calathea inside when temperatures start to drop in the early autumn. Calathea plants need temperatures between 15.5 and 21 degrees C (60F to 70F). In addition, their indoor locations should be free from draughts, and away from radiators and open windows.
Like most tropical plants, calathea love moisture and humidity. However, calathea need to be planted in well-draining soil and should never sit in water. You should plant them in containers that have draining holes that are at least 1.25 cm (1/2 inch) in diameter. Also, the container should sit on a layer of pea gravel spread on a saucer to help with the humidity. Houses tend to dry out in the winter when the heating is on all day. You can place a humidifier next to your calathea plant to ensure it stays moist. If you have room in the bathroom, place your calathea plant in the dampest room in the house.
Fertilise your plant if you notice leaf spotting or discolouration. Gardeners should use a fertiliser that has a nitrogen-phosphorus-potassium amount of 3-1-2 to help amend nutritional deficiencies in the plant. To fertilise, dilute the fertiliser according to the manufacturer's directions and apply the mixture around the edges of the pot. If your calathea plant has had no nutritional problems, you can use an all purpose fertiliser of 10-10-10 mix.