“Every Sunday” is easy to remember. It is a poor instruction for a pot that stayed wet all week. Use the calendar to remind yourself to look; let the plant, its potting mix and its species decide whether water is due.
Check the pot before you pour
Identify the plant and look up its moisture preference. Then feel the mix below the surface, not only the dry-looking top. University of Maryland Extension suggests checking roughly two inches down for many houseplants and comparing the pot's weight when wet and dry. That depth is a useful starting observation, not a command to let every plant dry by two inches. A tiny pot, an orchid in bark and a large peace lily do not share one target.
If the mix at the relevant depth is still moist and the plant has no urgent problem, check it again later. If it is dry to the level recommended for that species, water the potting mix thoroughly and let the excess leave through drainage holes. Empty the saucer or decorative outer pot. A pot with no drainage makes it difficult to correct excess water. An inner pot with holes lets excess water escape and keeps standing water out of the bottom.
Make the check repeatable. Use the same finger depth or a clean wooden stick at a safe point near the pot edge, and learn how the pot feels shortly after a proper watering. In a large pot, the surface may dry before the lower mix. In a small pot, a warm window can dry the whole volume quickly. Avoid stabbing through roots merely to reach an arbitrary depth; use the species' care guidance and more than one observation.
When you water, go slowly enough for the mix to absorb it. If water runs down a gap at the edge and exits immediately, a dry root ball may still be dry in the middle. Rewet carefully in stages and check the mix afterward. If water cannot leave at all, solve the drainage problem before repeating a heavy pour.
Read a wilted leaf with the soil
Wilting alone does not answer the question. A wilted plant in dry mix may need water; a wilted plant in wet mix may have impaired roots or another problem. Watering the second plant again can make the situation worse. Look for standing water, smell, soft stems and continuing decline. If those signs appear, inspect the roots and seek a species-specific diagnosis instead of following a generic “wait a week” rule.
For a plant that repeatedly dries out unusually fast, check whether roots fill the container or water runs down a gap at the edge of the mix. That is different from assuming a larger can or more frequent watering will solve it. Penn State Extension lists rapid drying and roots through drainage holes among signs to investigate for repotting.
Why the interval changes
Light, temperature, humidity, pot size, plant size, mix and drainage all change water use. Illinois Extension names these factors and recommends checking soil; a calendar cannot show current moisture. The same plant may use water faster after a move to brighter light or during active growth, and more slowly in a cooler, dimmer room. Check more often while conditions change; that does not mean pour more often.
For a contrast, indoor basil in a draining pot should not be allowed to dry completely, while rosemary is allowed to dry slightly between waterings, according to Penn State's indoor-herb guidance. Even those two herbs need their own pots checked because a shared day count cannot reflect both conditions. Seedlings and recently rooted cuttings require their own care instructions.
Write down when you checked, whether the mix was wet or dry, and whether you watered. A few observations reveal a useful interval for that plant in that room. Treat a new yellow leaf or unexpected wilt as a reason to inspect, not as an automatic order to add water.
Look at the record after a few weeks. If one plant was consistently dry every third day during a warm season, set a reminder to check sooner; do not schedule an automatic pour. If another remained wet for ten days, examine pot size, light and mix before the plant reaches the point of drooping. The interval changes with growth and seasons, so continue checking after moving the plant or changing its container.
Tell anyone else who waters the plants what the moisture target is for each species. A shared calendar saying "water all pots" can undo careful observation. A short note such as "check the mix under the surface, empty this cover pot" gives the next person a useful decision instead of a fixed quantity.
