By Dr. Bill Barrick, Executive Director
Begonias are one of the most interesting group of ornamental plants, with more than 1,000 species distributed throughout tropical and sub-tropical regions of the world. In 1978, Hortus Third, the published “Bible” for horticulture, indicated there were over 10,000 registered hybrids and cultivars of begonias. I would assume by now that number has doubled.
Begonias are divided into three main groups – fibrous rooted, rhizomatous rooted and tuberous rooted. Most all of the begonias are not cold hardy, and should be treated as either annuals or as potted plants carried over indoors during the winter months. Begonias are best grown in partial shade with good organic soils. By mid- to late July, many of the supposedly sun tolerant begonias planted in full sun in Mobile will suffer and not perform well.
Within the fibrous rooted category are the Angel Wing Begonias and Waxleaf Begonias. Over the past few years, we have been growing hanging baskets from cuttings taken from stock Angel Wing Begonias and have also planted the taller cane type begonias along the Exit Path. Although we do not plant many wax leafed begonias in the Gardens any more, I remember when they were the rage and planted everywhere. But I always thought they looked like pink, red or white cocktail meatballs. Even one series was named Cocktail, and named varieties were “Vodka,’ ‘Rum,’ ‘Gin’ and ‘Whisky.’
Over time, breeders have hybridized Angel Wing Begonias with Waxleaf Begonias, creating some of the most useful bedding plants for our Gardens. These interspecific hybrids have retained the best qualities of their parents, resulting in taller plants with a profusion of flowers. Planted along the South Terrace are ‘Dragon Wing Red’ begonias, and around the monument are ‘Surefire Pink’ begonias. In past years, we have good luck with the “Big” series.
The begonias that I am most excited about are hybrids of Begonia boliviensis. As the species name implies, this plant grows natively on the eastern side of the Andes in Bolivia and Argentina. Although we have only recently begun using some of the new hybrids, this species was first exhibited with acclaim in the International Horticultural Show in Paris in 1867. The pendulous habit of growth makes it excellent for hanging baskets.
Last summer, when I went to the Mall in Washington, D.C., I saw the most amazing hanging baskets planted in full sun around the Smithsonian Castle. This summer, near the Boehm Gallery we are using a variety named ‘Bossa Nova.’
In this series are ‘Rose,’ ‘Orange’ and ‘Red’ named varieties, all of which blend well in hanging baskets. I am hopeful they will perform throughout the summer, even though we have some planted in full sun and others hanging underneath our Live Oaks.
Also this summer, we are continuing our trials of tuberous begonias, which without question have the most stunning individual flowers. On the same plant are borne both male and female flowers. Like the world of birds, the males are the showiest with incredibly doubled flowers resembling either roses or camellias.
We are growing the Non-Stop series and are trialing both ‘Non-Stop Red’ and ‘Non Stop Rose’ named varieties. Since these begonias can easily be overwatered, we are using them in containers in shaded areas of the gardens.