Herblore of the Shire
The Hobbits had an astonishing habit: they imbibed or inhaled, through pipes of clay or wood, the smoke of the burning leaves of a herb, which they called “pipe-weed” or “leaf”, a variety probably of “Nicotiana”.
This is the one art that the Hobbits can certainly claim to be their own invention.
All the information about the pipe-weed was gathered by Meriadoc Brandybuck in the book called "Herblore of the Shire".
Origins of the weed
The weed itself was not native to Shire, but came northward from the lower Anduin, whither it was probably originally brought over Sea by the Men of Númenor.
It growed abundantly in Gondor, richer and larger than in the North, where it was never found wild, and flourished only in warm sheltered places. The Men of Gondor call it “sweet galenas” and esteemed it only for the fragrance of its flowers. From that land it must have been carried up the Greenway during the long centuries of the Third Age.
Beginning of its cultivation
When Hobbits first began to smoke is not known, all the legends and family histories take it for granted; for ages folk in the Shire smoked various herbs, some fouler, some sweeter.
But all accounts agree that Tobold Hornblower of Longbottom in the Southfarthing first grew the true pipe-weed in his gardens in the days of Isengrim the Second, about the year 1070 of Shire- reckoning (2670 TA).
How Old Toby came by the plant is not recorded, for to his dying day he would not tell. He knew much about herbs, but he was no traveller. It is said that in his youth he went often to Bree, though he certainly never went further from the Shire than that. It is thus quite possible that he learned of this plant in Bree. The Bree-hobbits claim to have been the first actual smokers of the pipe-weed.
Spreading to the outer world
It was from Bree that the art of smoking the genuine weed spread in the recent centuries among Dwarves and such other folk, Rangers, Wizards, or wanderers, as still passed to and fro through that ancient road-meeting. The home and centre of the art is thus to be found in the old inn of Bree, The Prancing Pony,
The best home-grown came from Longbottom, especially the varieties known as Longbottom Leaf, Old Toby, and Southern Star.
Concerning Gandalf and Saruman
Gandalf was among the first to be interested in the pipe-weed. He had been exercising the habit for long. Saruman, who was always jealous of Gandalf, had observed his passion with the herb and had affected to scoff at it, but in private he made trial of it, and soon began to use it; and for tins reason the Shire remained important to him. Yet he dreaded lest this should be discovered, and his own mockery turned against him, so that he would be laughed at for imitating Gandalf, and scorned for doing so by stealth. This then was the reason for his great secrecy in all his dealings with the Shire even from the first before any shadow of doubt had fallen upon it.
Gandalf’s opinion about the weed, expressed to Saruman once at the White Council:
“You would not wonder if you used this herb yourself. Yon might find that smoke blown out cleared your mind of shadows within. Anyway, it gives patience, to listen to error without anger.”