Triage for a 500-Plant Cactus Collection with Pests, Rot, and Cold Damage

Inherited 500 cacti moved from greenhouse to basement (neglected), now back in greenhouse with scale, spider mites, rot, and possible freeze damage (below 40°F). Priority actions: 1) Discard all diseased/infested plants—too many to treat. Isolate keepers if sentimental. 2) Spray survivors with insecticide/fungicide combo; repeat in 2 weeks. 3) Separate cacti from succulents (non-spiny or single spines). 4) Move outside, scrub greenhouse with bleach, add fans for airflow. 5) Repot pot-bound plants in fresh soilless mix with bonemeal, blood meal, superphosphate, fungicide (1 tsp each per 8–10 gal soil). 6) Discard frozen plants; inspect others for delayed rot. 7) Water dry plants; wait 2 days after repotting before watering. Keep outdoors for summer. Phase repotting—start with worst cases. Babies can go in dish gardens. Email for ongoing support.