A rattlesnake calathea plant prefers bright, indirect light and consistently moist but not waterlogged soil. Keep it away from harsh direct sunlight, which can damage its patterned leaves. Water when the upper layer of soil begins to dry, and avoid letting the plant sit in excess water. Calatheas generally appreciate higher humidity, so placing the plant near a humidifier or grouping it with other plants can help. Keep it away from cold drafts and sudden temperature changes. With suitable light, moisture, humidity, and warmth, the plant can maintain healthy, attractive foliage.