Watering:
Calathea must be kept in damp soil at all times, but definitely do not allow the plant to sit in water or in very wet soil. Never allow it to dry out.
Fertilizer:
Throughout the growing season, fertilize with light liquid fertilizer. In the winter, reduce fertilizer application to once a month or less.
Re-potting:
Rattlesnake plants typically need to be re-potted every year or two. Wait until the roots have filled the soil.
Temperature:
Prefers warm to high temperatures, ideally between 21-29°C