Harvesting Sassafras

When and how does one harvest the sassafras root for tea? How deep does one dig? Do you use the roots closest to the surface or does one go deeper and try to capture larger more mature roots? Can and how would one damage a tree by digging the root? What time of year is best? Does it matter where the moon is? :)

The usual practice is to dig up young saplings in the fall. This destroys the saplings, but more saplings will grow up taking the place of the ones you harvest. You can also dig larger roots from a more mature tree, but there is always a risk that the tree will be damaged by the digging. The young saplings are much easier to dig.
As for when to harvest in relation to the moon, we have no information on that. It is true that the moon can affect plants, but what that effect is and when, we have for sassafras.