Indoor Transition Shock: Saving a 10-Year Cactus from Rot

Likely Cause: Overwatering in Low Light

Moving outdoors→indoors reduces evaporation. Monthly watering may now be excessive. Cold window + low light = rot initiation.

Survival Assessment

Once rot starts upward, chances drop. But attempt rescue:

Immediate Steps

• Ensure 4+ hours direct sun.
• Maintain 70°F+ (growing), 60°F (winter).
• Water ONLY when soil bone-dry.

Pruning Decision

• Multi-branched: remove dying branches.
• Single/double stalk: don't cut top—new growth comes from apex.
• Repot if pot-bound or wrong soil (use cactus mix).

Identification Needed

Photo would enable species-specific advice. "Spike" deserves targeted care.