In a story about sansevieria, La Nación described a household method of raising a pot on clean soda-bottle caps. The trick does not replace drainage holes and proper watering.
Sansevieria, also known in Spanish-speaking countries as mother-in-law’s tongue, is a popular houseplant that tolerates dry periods. However, overwatering can harm roots that are sensitive to constant moisture.
La Nación says caps should not be placed at the bottom of the pot because they take up space for roots and do not guarantee better drainage. Instead, clean soda caps can be used as small supports under the pot, if its base has drainage holes.
Penn State Extension recommends using pots with drainage holes and leaving space for water to flow freely. It also warns that a layer of pebbles at the bottom of a container does not improve drainage and can retain moisture.
Caps under the pot may keep the drainage holes from resting against a flat surface, but they do not solve overwatering. After watering, excess water collected in a saucer or outer cachepot should be emptied.