Wax Begonias With White & Black Leaves

Rex Begonia

• The Rex begonia (Begonia rex) has leaves that come in a wide variety of colors, including a deep, dark, maroon that appears black, and a silver or gray that can look white. Its leaves may also be green, lavender, pink or red. Gardeners normally plant Rex begonias for the color of their leaves, rather than the hue of their flowers. The plant enjoys partial shade and rich, well-drained soil.

Silver Sweet

• The leaves of a Rex begonia are extremely fragile; so much so that even a hard rain can easily rip through the delicate foliage. The soil of the plant should be kept somewhat dry, but not so much that the leaves wilt. An additional Rex begonia cultivar with leaves that bear shades of white or black is the Silver Sweet cultivar, a plant that has leaves that often appear as a shade of white.

White Problems

• The leaves on a wax begonia may turn white if it is infected by a common begonia pest, the giant whitefly. This insect coats itself with a white, waxy secretion and a large infestation of the pest can cause the leaves to take on a distinct, white color. Immature whiteflies have long, filaments of white hair that protrude from begonia leaves as much as 2 inches. The fungal disease known as powdery mildew also produces a white, fungal dust on the leaves of a begonia.

Black Problems

• The aforementioned giant whitefly causes the leaves of a wax begonia to turn both white and black. In addition to the white, waxy covering on their body, the waste product of the giant whitefly -- honeydew -- sticks to leaves of the begonia and attracts a fungus that causes the condition known as black sooty mold. This sticky fungus greatly decreases the aesthetic value of the plant and attracts ants, a pest that detracts from the ability of the natural predators of the whitefly to properly control it.