Wax begonias, or fibrous begonias, are annual plants. These brightly colored bedding begonias are equally at home in full sun (except where temperatures stay above 90 degrees Fahrenheit for days on end) or full but bright shade (where trees are pruned high). From first setting them out until they are laid low by frost, they'll be packed with white, pink, rose, or red blossoms. Virtually untouched by bugs or blight, their only shortcoming is a relatively narrow color range. They are widely available in market packs.
Description: Uniformity is the trademark of most wax begonias: tight mounds of closely packed leaves covered with blossoms. All four flower colors are available with your choice of leaf color: chocolaty-red or shades of green. The deeper-colored or bronze-leaved varieties offer especially eye-catching contrast with flowers. There are also varieties with double flowers that resemble fat little rosebuds and others with variegated foliage.
How to grow: Fibrous begonias perform well in rich, well-drained soil, but the soil must be allowed to dry between waterings. They'll form tight, compact plants in full sun, with increasingly looser form and fewer flowers as you move them deeper into the shade. Most hybrids will grow six to nine inches high and spread as wide.
Propagation: Most hybrids are grown from seed, but great patience is required. Dustlike seeds (two million per ounce) must be sown in December or January for large, husky plants by May. Germination temperature is 70 degrees to 85 degrees Fahrenheit and requires 14 to 21 days. Cuttings root readily, so an easier way to start plants is on a sunny windowsill during fall and winter.
Uses: Wax-leaved begonias lend themselves to large, formal plantings because of their uniform size and shapeliness. They're also suitable in front of summer annual borders and combine well with other cool-colored flowers in mixed plantings and containers.
Related varieties: Popular, dark-leaved kinds are the Cocktail series: Brandy, Vodka, Whiskey, and Gin. Good green-leaved varieties are found in the Lotto and Pizzazz series. Avalanche begonias in pink or white are rangier, suited for containers and hanging baskets, where their arching growth habit is handsome.
Scientific name: Begonia semperflorens