Iron Cross Begonia Begonia masoniana

Iron cross begonia is a tender, herbaceous perennial, typically grown as an ornamental houseplant, that is native to China and Vietnam and is a member of the Begonia family (Begoniaceae). It grows from a rhizome and is noted for its unique foliage, rather than its seasonal greenish/white floral display. The dark chocolate center marking in the leaves resembles the Iron Cross used on shields during the Crusades. The Latin species name honors L. Maurice Mason, English plant collector, who brought this plant from Singapore back to England in 1952 and gave it the common name of iron cross.

The plant is hardy to USDA zones 11 and 12, preferring temperatures in the low 70s, and will not survive outdoors in temperatures below 55 degrees F. When grown as a houseplant, place it in bright but indirect or filtered light (for example, a southern, eastern or western window), use moisture retentive potting mix and keep evenly moist during periods of growth. When active growth slows down, slightly reduce water applications, allowing the surface of the soil to nearly dry before adding water.. Although this plant prefers high humidity, which can be increased by placing the pot on a gravel tray filled with water, it must not be overwatered. Iron cross begonia can be propagated by stem or leaf cuttings.

Insects, Diseases, and Other Plant Problems: Keep foliage dry to help prevent the onset of powdery mildew. Susceptible to bacterial leaf spot, blight, and stem/crown rot. Watch for aphids, mealybugs, and spider mites. Plants taken outdoors in summer are susceptible to slugs and snails if pots are placed on the ground.

VIDEO Created by Elisabeth Meyer for "Annuals, Perennials, Vines, and Groundcovers" a plant identification course offered in partnership with Longwood Gardens. 

More information on Begonia – Rhizomatous Types.