Tarragon's name is taken from the French esdragon, which mans "little dragon" because of it's serpentine root system, which will actually strangle the plant if it is not divided often enough.  It is bound to Mars and Fire.  It is known as a protective and calming herb and is used in kitchen magic to put guests at ease and make them feel welcome.  It is used in the consecration of chalices, and can be carried in charms or sachets for compassion love, peace, nurturing, and good luck. 

Tarragon can also be used as a banishing herb.  Use as an incense as you write down the thing you want to banish on a white piece of paper and then burn the paper in a suitable container.