Bulbous Roots. The time to put these in is from September to November, and the earliest ones will begin blowing about Christmas. The glasses should be blue, as that colour best suits the roots; put water enough so as to cover the bulb one-third of the way up, less rather than more; let the water be soft, change it once a week, and put in a pinch of salt every time you change it. Keep the glasses in a place moderately warm, and near to the light. A parlour window is a very common place for them, but is often too warm, and brings on the plants too early, and causes them to be weakly.