Scabby Cacti: Reader Rates Expert Poorly, Greg Responds

Light Brown Scabs Spreading on 70% of Collection After Record Heat

A long-time grower describes "blisters of crackly light brown scabs" on medium cacti. In the past, cutting out small spots worked; now 70% affected after record Chicago heat/sun. She rated Greg poorly for not knowing the exact cause.

Greg's Reply: Volunteers Do Their Best With Limited Info

Greg (35+ years collecting, no formal training) expresses frustration: non-descript questions expecting textbook answers drive volunteers away. He advises asking follow-up questions before rating poorly.

Possible Causes of Scabs

• Sunburn/heat stress (record heat).
• Edema (water uptake > transpiration).
• Fungal/bacterial lesions.
• Insect damage (mites, scale).

Action: Send clear photos to greg8365@hotmail.com for diagnosis. Improve airflow, reduce watering during heat waves, provide light shade during peak sun.