Water your tuber sparingly until growth begins. The idea is that the terrarium will act as a greenhouse, retaining moisture and helping your begonia grow. You also want to make sure you place your begonia
in a sunny location in your home. Even though begonias are shade plants, when they are getting started they need a little more sun.
Depending on the temperature of your home (best temps for starting begonias ranges from 65-75 degrees F), you will see sprouts in around 10-12 days. This can vary, so just be patient. When your begonia
sprouts to the size of the pot on the right (above), remove the terrarium. It may take 5 to 6 weeks to see significant growth above the soil line. Water when the soil is dry to the touch.