Them Dwarven folk.

[zxcvbn]

Originally Posted by Aganzir

Smoking of pipe-weed spread among Dwarves from Bree, says the Prologue. I don't remember what else has been said about pipe-weed, but it's hard to believe it grows only near the Shire, so trade isn't necessarily needed for the dwarves to get it.

Bree is even farther from the Blue Mountains than the Shire. And it's unlikely that the Dwarves grew it themselves, as it needed open spaces and lots of sunlight. And the Elves didn't smoke, so they wouldn't grow it either. So trade it is.