Start indoors in a well-lighted area 3 months before planting time. Sow very shallowly in seed-starting formula as seeds need light to germinate well. Keep moist.
How to Grow
Seedlings emerge in 15-21 days at 70°F. Transplant to individual containers when seedlings have at least 2 pairs of leaves. Before transfer to garden or containers, accustom seedlings to outdoor conditions by moving to a sheltered place outside for a week. Once planted, wax begonias need almost no care beyond watering during dry weather. For tuberous begonias, insert thin stakes next to tall cultivars at planting time, and use yarn to tie the stems loosely to the stakes as they grow, since the brittle stems break easily. To keep plants for another year, dig the tubers when frost threatens. Dry them in a protected, shady, well-ventilated spot, remove any excess soil, and store in boxes or shallow trays filled with dry peat moss at 45ºF.
Use wax begonias in containers and as edgings, as miniature temporary hedges, or in shade gardens to add summer-long color. They make a great filler over daffodils and other spring bulbs. Tuberous begonias can be grown in containers or with other shade plants, such as impatiens, browallias, and lobelias. In the ground, they are lovely combined with ferns and other shade-loving perennials. Keep them set back from walkways, as the stems are brittle and easily broken. Plant hardy begonias in a shaded site with hostas, lungworts, barrenworts, hellebores and ferns.