Look below a healthy-looking crown
A rosette can appear attractive while its roots or lower stem have deteriorated. If it suddenly becomes loose, check the root ball and base rather than pressing it deeper into wet mix to hold it upright.
Preserve sound roots where possible and remove clearly deteriorated material with clean tools. Repot into an appropriate draining setup if required. If only healthy top growth remains, confirm a suitable propagation method for that plant instead of assuming every rosette roots the same way.
FAQ
Will fertilizer make a loose plant anchor quickly?
Not if the connection or roots are damaged. Establish the cause before feeding.
Source
RHS: Growing houseplant cacti and succulents
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