Botanical Name: Begonia masoniana
Iron cross begonia leaves are easily recognizable. Each bright-green puckered leaf is marked with a reddish-brown iron-cross pattern in the center.
You may see sprays of pinkish-white flowers in spring and summer, but these blooms are insignificant compared to the magnificent foliage. Pinching off flower buds will promote bigger, healthier leaves.
Iron cross begonia looks stunning when planted with other fancy-leafed begonias, such as Begonia Rex. Their contrasting leaf textures, colors and patterns complement each other in a dish garden.
If your plant suddenly collapses and shrivels up, don't give up on it. It's not uncommon for this begonia to go dormant in winter. While it's tempting to overwater a withered plant -- stop watering during dormancy. What this handsome begonia really craves is high humidity. Cover the plant with plastic or a glass cloche and keep the plant around 60°F/16°C for 6-8 weeks. You'll see new leaves appear.
Shed some light. Give your begonia bright, indirect light. You'll get the best leaf color this way. It thrives under fluorescent lights.
Repot in spring. Move your plant up to a pot only 1 size larger. Using a small pot with a drainage hole will help to prevent overwatering. Tamp down the soil gently with your fingers so that it doesn't pack too tightly -- begonias like a little air around their roots.
Don't overwater. This is one of the few problems with growing begonias. Begonia masoniana has rhizomatous roots that store water, so allow the soil to dry out slightly between waterings.
Also watch for powdery mildew on leaves and stems. Poor air circulation and high humidity are favorable conditions for this dusty, white fungus. Cut off affected leaves and be sure your plant has air circulation around it. However, keep it away from heat/AC vents, which can be drying. Treat foliage with a fungicide when needed.
Origin: Southeast Asia
Height: Up to 1 ft (30 cm)
Light: Bright, indirect light. It also thrives under fluorescent lights.
Water: Water thoroughly, allowing the top 1 in (2.5 cm) of soil to dry out between waterings. Avoid getting water on the leaves because they spot easily and are prone to mildew.
Humidity: This fancy-leaf begonia likes higher-than-average humidity. If the air in your home is dry, use a room humidifier or place pot on a tray of wet pebbles to increase humidity. Grouping tropical plants such as begonias, ferns and orchids also helps to increase the moisture in the air around them. Misting begonias is not a good idea because it can promote powdery mildew and fungal diseases.
Temperature: Average room temperatures 65-75°F/18-24°C. Begonias are not cold-tolerant and can be damaged by temperatures below 50°F/13°C.
Soil: Peat moss based, such as African violet potting mix.
Fertilizer: Feed monthly year-round with a 10-10-5 liquid fertilizer diluted by half. Fertilize when the soil is already moist to avoid fertilizer burn. Don't feed a dormant plant.
Propagation: Stem cuttings root easily. Take 3 in (8 cm) stem cuttings with leaves in early summer and root them in moist, sterile potting mix. Cover with plastic or a glass cloche to raise humidity around it until new leaves form.