Keep the soil lightly moist but never waterlogged. In winter, plants dry out more slowly, so water only when the top of the soil feels dry to the touch, and always water in the morning so the leaves can dry before night. Too much water leads to yellow leaves, root rot and mould, which are the most common beginner mistakes. If the pot has a saucer, empty it after watering. A thin layer of mulch, such as dry leaves or straw, helps hold moisture without keeping the soil soggy.
