Rex Begonia

bright indirect light (3-6 feet from a south or west window, or right next to an east window. Under a grow light, 6-10 inches away works well); they tolerate lower light than flowering begonias since they are not grown for blooms. East-facing windows or filtered light (behind a sheer curtain, or set back 2-3 feet from a sunny window. A grow light 8-10 inches away works well) from a south window work well. Washed-out leaf color means too little light; crispy patches mean too much sun.

Requires 60-70% humidity for best color and growth. Use a pebble tray or humidifier. Never mist directly onto the leaves.

Well-draining mix rich in organic matter; coco coir plus perlite or vermiculite works well. Use a wide, shallow pot to accommodate the spreading rhizome.

Powdery mildew and botrytis are the most common problems; both are caused by wet foliage or stagnant air. Root rot from overwatering is also frequent. Mealybugs can be persistent. In winter dormancy, resist the urge to overwater a plant that has dropped its leaves -- wait it out.