Underwatering lily can lead to wilting of the leaves, drooping stems, and overall poor growth. The soil may appear extremely dry and crumbly. On the other hand, overwatering lily can result in yellowing or browning of the leaves, with a potential increase in leaf drop. The soil could become excessively wet and may have a foul smell. Additionally, overwatering can promote the growth of mold, fungus, or rot, which is detrimental to the plant's health.