A “Hardy Begonia” is somewhat of a misnomer for the small-flowered, tuberous-rooted Begonia plant we call Begonia evansiana. This Asiatic species, known to the Chinese for centuries as Tsou Hoy Tong, was used as a motif both by the Chinese and the Japanese in decorating china, fans and silks.
When first noticed by botanists, it was tentatively called Begonia discolor until a better name might be found for it. But after it was collected for T. Evans in 1804 by William Kerr, Henry C. Andrews, author of Botanist’s Repository, introduced it under the name of Begonia evansiana – Evans begonia or Begonia grandis subsp. evansiana.
Sprays of Pink
Although the blossoms which appear in our backyard landscape in late August are much smaller than the tuberous-rooted begonias now so much in vogue, the long-stemmed sprays of pink flowers are almost as striking as a large, single bloom. They contrast pleasingly with the shiny yellow-green leaves which are heavily veined underneath with red.
The characteristic that makes this begonia species unique is its method of reproduction from the bulblets which are borne in the axils of the leaves. These drop to the ground, and under favorable conditions this tuberous begonia plant will spread rapidly. In fact, in greenhouses they find their way into every nook and cranny to become a nuisance.
Although it does not seem to produce seed, the blossoms have been successfully used as a male parent in crosses with rex begonias. This hybrid group is known as discolor-rex. The best-known of these is one called Abel Corriere, which has the branching habit of Begonia evansiana, but with silver leaves broadly veined with green on the upper side. The underneath side is green, and has the prominent red veins of its male parent. When mature, the leaves flush a deep rose purple to complement the pink sprays of flowers.
Meaning of Hardiness
Just what do we mean by its hardiness? One University reported that plantings there (Indiana) survive periods of 10 degrees below zero without protection except from fallen leaves of nearby trees. However, this is the exception, rather than the rule. Where temperatures get down too low, your Begonia evansiana is much more likely to stay with you if given a two-foot mulch of straw as soon as the ground freezes. One reader from of Omaha successfully followed this method for a number of years, and her plants of Begonia evansiana evoke exclamations from all visitors to her backyard garden landscape either in bloom or out.
Another reader in Kansas, reports that Begonia evansiana refuses to live out-of-doors for her, despite heavy mulching, and must be lifted and carried over indoors, much as we would zephyranthes. She advocates storing both the larger bulb of the mature plant, as well as the bulblets, in flats of dry soil in a cool basement.
Treat as Tender Bulb
If this method is to be followed, the bulbs should be dug as soon as the first sign of frost has nipped the leaves. All water should be withheld until late March when growth may be started for early planting.
Whether you are planting B. evansiana for the first time or have carried bulbs over in the house, prepare a bed on the north side of the house by digging in enough peat or leaf mold to make the ground friable. Set the bulbs out in late May or early June as soon as all danger of frost is past, and keep moist for maximum performance.
Although B. evansiana has not always proved completely hardy for me, the bulbs cost no more than those of other tuberous begonias or even potted tender plants which we may grow for a season and discard.
