Red Oxalis

Bright indirect to direct light indoors. It handles direct sun (right in the window where sun actually hits the leaves. A strong grow light 4-6 inches away can substitute) through a window well but can scorch if moved suddenly from low light (more than 8 feet from a window, or a north-facing room. A grow light 10-12 inches away works great if your windows are not cutting it) into harsh outdoor sun. Not suited for dark spots -- insufficient light produces leggy, weak stems and fewer flowers.

40-60% humidity is the comfortable range. It tolerates average indoor conditions but benefits from a pebble tray or nearby humidifier in very dry rooms. Keep it away from heating vents that dry out the air rapidly.

Well-draining potting mix is essential. Standard potting soil with added perlite or coarse sand works well -- the plant needs moisture retention balanced with fast drainage. Heavy or compacted soil leads to tuber rot.

Root rot from overwatering is the main issue. Watch for aphids, spider mites, mealybugs, and whiteflies -- treat promptly with insecticidal soap or neem oil. The plant goes dormant when stressed by heat, drought, or cold; do not discard it when the leaves die back -- check the tubers and resume normal care when new growth appears. Rust fungus (Puccinia oxalidis) is an occasional problem.