Galanthus G . nivalis the common Snowdrop grows approx. 100mm-200mm high and should be planted out approx 100mm-150mm apart, they generally flower from January onwards.
They will survive in most soils but prefer heavy loamy soils that hold plenty of moisture. They do well in open woodland or in shrub beds provided they get good light.
The bulbs can dry out rapidly if left in the open so it is best to transplant immediately after flowering, and before the leaves die back, plant them to the same depth as before.
This method is known as 'planting in the green'