Calamondin Orange

full sun (6 or more hours of sun hitting the leaves per day. South-facing window, no obstructions. Under grow lights, keep them 4-8 inches away for 12-14 hours) is non-negotiable - at least 4 hours of direct sunlight per day. A south-facing window is ideal. Insufficient light directly reduces flowering and fruiting. If natural light is limited in winter, a grow light supplement makes a meaningful difference.

moderate humidity (40-60%. Most homes are fine, but a pebble tray helps in winter when heating dries the air out) (40-50%) is ideal. Dry air can cause flower drop before pollination. A pebble tray under the pot or morning misting (note: misting does not actually raise humidity meaningfully. A pebble tray or humidifier is more effective) (avoiding direct sun) helps. Avoid misting (note: misting does not actually raise humidity meaningfully. A pebble tray or humidifier is more effective) in direct sunlight, which burns the leaves.

Free-draining, slightly acidic mix. A commercial citrus compost or equal parts loam, leaf mold, and horticultural grit works well. Terracotta pots are ideal as they prevent waterlogging. pH should be around 5.5-6.5.

Scale insects, spider mites, and mealybugs are the main pests. Flower drop before fruiting is usually a humidity or temperature stress issue. Yellowing leaves typically indicate overwatering, poor drainage, or iron deficiency in alkaline soil. Indoor plants need hand pollination - use a small brush to transfer pollen between flowers to trigger fruit set.