My regular gardening books are strangely lacking in how to grow absinthe but a web-trawl revealed that it's commonly known as wormwood, is extremely bitter and is, indeed, the key ingredient in the drink that put the fin in fin de siècle.
Artists, poets and writers all indulged in this seductive green drink, probably because it was said to make you more creative.
Hmm. An on-line recipe calls for vodka and several herbs that are already growing in the garden. I find myself strangely attracted to the idea of an absinthe evening...especially now that I've learned the correct way to pour it.