These plants like slightly damper soil conditions than most other begonias. When the top of the soil feels dry to the touch, water thoroughly in the morning using tepid water. Discard excess water from the run-off dish after 15 minutes. (Plants deteriorate rapidly if left in a wet dish.) Allow to remain dryer in winter but do not let the potting medium dry completely. Do not let the leaves get wet when you water. High mineral content in water may result in cosmetic damage to leaves.

Keeping the balance of soil that remains moist but drains well during the growing season can be very challenging but steady humidity helps. A relative humidity above 50% is important to successfully grow Rex Cultorum Group begonias and a few plants need as much as 80% humidity. (If your plant has a thin or silky leaf texture, it is likely to need greater humidity.)  Crispy leaf margins will tell you that your plant requires greater humidity. Provide additional humidity by standing plants on shallow trays filled with moistened pebbles and/or using a humidifier. Misting may allow water to settle on the leaves causing spots, so it is not recommended. A simple hygrometer kept in the area of the plant will help you to monitor air moisture.

Make sure that plants are well-spaced and have good air circulation so leaves don't stay damp and rot.

Read more about caring for your plant in our Guide to Rex Cultorum Begonias.

Courtesy of NYBG Plant Information Service