Yucca Root Rot and Fungus: Immediate Repotting to Terra Cotta

New 6-foot yucca from IKEA in small black pot; nursery said wait until spring to repot to 20-inch terra cotta. South window; bottom leaves dying; mushrooms in peat soil.

Expert Override: Repot NOW

• Fungus = overwatering in peat soil.
• Repot immediately to terra cotta (max 4 inches larger diameter).
• Soil mix: 1/3 potting soil, 1/3 perlite, 1/3 builder's sand.
• Water meter: Buy one—surface dry ≠ root zone dry.
• Water schedule: Fall/winter: dry 1 week before watering. Spring/summer: dry 3–4 days.
• Light is fine.

Terra cotta breathes; sandy mix drains; meter prevents overwatering.