Placement

Bonsai trees need a lot of light to properly grow. During winter, indoor bonsai trees should be placed next to a window to receive as much light as possible. You should also turn the pots regularly to ensure that every side gets an equal amount of light. During spring and summer, you can place your indoor bonsai outdoors, but be mindful to gradually increase the amount of direct sun that your bonsai tree will receive. Always avoid south exposition as it would heat the pot, soil, and roots, and potentially damage your bonsai. Outdoor bonsai trees can stay outside all year long. Direct sunlight is OK during winter, but always avoid it during summer, no matter what type of bonsai tree you are growing.

Temperature

Outdoor bonsai trees need cold temperature in winter to activate dormancy. In summer, outdoor bonsai trees like warm temperatures, but make sure to water accordingly during peak season to avoid dehydration. Indoor bonsai trees also need lower temperature in winter, but they do not tolerate frost so make sure to keep them in a warm enough place.

Watering

Never water a bonsai tree on a routine. Watering for bonsai trees will depend on their type, on the season, on the humidity level in the air, and on the temperature. To know when to water a bonsai, check the soil: if the soil begins to dry, it is time to water your bonsai tree. Never wait for the entire soil to be dried out as at this stage your bonsai tree will already be suffering from dehydration. Water as soon as the soil is no longer moist, but do not saturate the soil. Also, never leave stagnant water below the pot as this would cause the roots to rot.