In general, with all plants, the leaves should not become wet, as this encourages the development of diseases. Pot plants are best watered from below.
For the right watering time, a simple principle is always to water the plant in the pot as soon as the earth feels dry. If an indoor plant receives too much water, its roots can easily become waterlogged and rot and the plant could die. In contrast, pot plants which have dried out due to a lack of water can often still be rescued by placing them in a bucket full of water for some time until the earth has become completely saturated. If the pots stand in an outer pot without a drainage hole, the excess water must be emptied regularly.
In summer it is best to water in the early evening hours or in the early morning. Especially when temperatures are very hot during the day, the water quickly cools the roots down, which then reduces their capacity to absorb it. On hot, sunny days, no water should remain on the leaves either, as this damages the plant fibres when burnt by the sun.
In winter, pot plants should be watered in the morning. In the evening, stagnant water can reduce the temperature as far as into the roots and thus also reduce the ability to absorb water.
The pot plant root balls should never completely dry out in winter. For this reason, it is important to water regularly but little, so that the plant has a constant supply of water. In general: Be careful when watering in your winter quarters. Unfortunately, there is no generally-applicable rule for watering. However, the following always applies: The lower the temperatures, the less often your plants should be watered.
It is normally better for pot plants to water generously but less often. In this way, the plants build up water reserves and can easily withstand periods without being watered for several days.