Calathea: Greenhouse Plants
W – warm, minimum of 13°C (55°F)
To get the best out of these attractivethey should really have tropical conditions. However, if this is not possible they can still be grown. If the temperature is below 15°C (60°F) in winter they will exist rather than grow and should be watered very carefully with the surface of the drying out between waterings. They will pick up and grow as soon as the temperature rises in summer. They are naturally forest floor plants and prefer warm moist shady conditions. If the atmosphere is too bright and dry they will become scorched and be more prone to red spider mite which is their worst enemy. At least it is possible to spot these pests easily as they stand out against the purple undersides of the leaves. Calathea makoyana, which grows to 60 cm (2 ft), is called the Peacock Plant because of the beautiful markings on the leaves. C. insignis from Brazil is the smaller Rattlesnake Plant with horizontal olive-green markings on its long wavy leaves. C. ornata from Colombia has thin juvenile leaves that are white or striped with white. On older plants leaves become darker and are a deep maroon beneath. C. zebrina, a Brazilian species, has bold stripes and appears to exist in two forms: some plants are very small whereas others reach a stately 90cm (3 ft) without any trouble. Being used to light leaf litter in their natural state they prefer a well-drained peaty compost rather than one based on loam which tends to become very stodgy under the conditions they like. Propagation is by division, best done in summer when they are potted.