There is no fixed schedule for watering houseplants, as frequency depends on the type of plant, pot size, soil mix, light levels, and time of year. As a general rule, you should water only when the top two to three centimetres of soil feel dry. Overwatering is far more common than underwatering and can lead to root rot, yellowing leaves, and fungal issues.
During spring and summer, plants typically require more frequent watering due to active growth and increased light. In autumn and winter, growth slows and watering should be reduced. Always ensure your pot has drainage holes and never allow plants to sit in standing water.