Which of the following is NOT a general rule for caring for bonsai?

Allowing the pot to dry out is not a general rule for caring for bonsai because these trees require consistent moisture in their soil to thrive. While it is important for bonsai to have proper drainage and not to sit in stagnant water, completely drying out the soil can stress the plant. Bonsai are often kept in shallow pots, which can dry out quicker than standard pots; therefore, careful watering is essential to maintain the right level of moisture.

In contrast, the other options are vital best practices for bonsai care. Feeding periodically ensures that the bonsai receives essential nutrients, which is necessary for growth and health. Using a good, loose potting soil mixture promotes proper drainage and aeration, allowing roots to breathe. Repotting at least every two years helps to refresh the soil, preventing nutrient depletion and allowing for root pruning, which can promote healthy growth.