Indoor Cactus Care After Furnace Upgrade: Heat, Water & Soil

Kathie's 15-year cactus collection thrived on a south windowsill with monthly watering. After installing a forced-air gas furnace and vinyl windows, she lost the windowsill, moved plants to a dining table near a heat vent, and all four new cacti rotted within 6 months despite the same watering schedule.

Jeff identified the heat vent as a likely killer—cacti need ambient air, not hot, dry blasts. He also noted commercial soils often lack drainage; adding pumice, perlite, or gravel helps. Cacti have a winter rest period needing only light watering; a fixed monthly schedule ignores this. They also need cool nights.

He recommended keeping the south window location but adjusting watering to the plant's growth cycle: minimal in winter, increasing in spring.

Revised Care Routine

• Move away from heat vents.
• Amend soil with 50% inorganic grit.
• Water lightly in winter; resume regular watering in spring.
• Ensure nighttime temperature drop.