Tuberous begonias (Begonia x tuberhybrida) offer a wide variety of long-lasting colors and shapes. These tropical natives require shade, well-draining soil, and consistent moisture to thrive in the garden setting. Slow-growing tubers take 12 to 14 weeks from planting to bloom; for earlier shows, start tubers indoors as early as eight weeks before the last expected frost. No matter the variety, begonias add a wealth of color to any garden setting.
Tuberous begonias can be reproduced by a variety of cutting methods, including stem or leaf cuttings and division. All cutting methods, with the exception of leaf section cuttings, can be rooted in either water or sterile potting mixes.
Tuberous begonia seed, whether retail or harvested from existing plants, is the slowest method of obtaining new cultivars. The minuscule seeds measure one million seeds per ounce and are very tricky to sow. Seed retailers often coat begonia seeds with clay or similar material to increase handling ability. Growing tuberous begonias from seed takes 18 to 20 weeks from planting to bloom stage, making this one of the least desirable resources.
Greenhouses and Nurseries
Local, mail-order or online greenhouses and nurseries are excellent resources for finding tubers or starter plants. When shopping locally, select tubers that are large and free of shrinkage or damage. Smaller tubers will produce less than favorable results, and shriveled specimens may not grow at all. When shopping through mail or online, choose retailers that offer a money-back guarantee if you receive tubers that are less than favorable.
Local or online gardening communities that focus on begonias may be a great resource for finding new and rare tuberous begonias for trade. Contact your local agricultural extension agency for information on local groups. There are many resources, such as forums and communities, online for begonia growers. The American Begonia Society offers a listing of chapters by state where you can obtain further information on tuberous begonia purchase or trade resources (see Resources).