As their name suggests, Cascade Begonias provide a waterfall of softly beautiful blooms which will flow over the edges of containers, hanging baskets or window boxes. The plentiful double Cascade Begonia blooms will provide a river of vibrant colour, which is sometimes so densely packed very little of the foliage can be seen peeking through it. The small Cascade Begonia flowers with their frilly petals give the effect of a myriad of small dainty roses. Keep your begonias where they get indirect light and water them just enough and no more. Cascade Pendula Begonia Bulbs grow to a height of 12 to 16 inches or 30 to 40 cm.