Look beneath the nursery container
A drainage hole works only if surplus water can leave the root environment. Lift the inner pot after watering and check whether the decorative cover has collected a reservoir. Repeated refilling can keep roots wet even when the visible surface seems normal.
Drain excess and keep the inner container stable without blocking its outlet. Do not rely on stones beneath it to make an unsuitable watering routine safe. If decline continues, inspect the roots and medium rather than adding fertilizer.
FAQ
Does every cover pot need replacing?
No. It can remain useful if water is removed and drainage is checked consistently.
Source
RHS: Growing houseplant cacti and succulents
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