One who smells a fragrant plant must recite before smelling either the Beracha of "Boreh Aseh Besamim" or "Boreh Asbeh Besamim." The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) presents a number of guidelines to determine which of these two Berachot one recites (listen to audio recording for precise citation). He writes that one recites "Boreh Aseh Besamim" if all three of the following conditions are met:
1) The plant has a hard, solid stalk.
2) The plant grows by itself each year, and does not have to be replanted.
3) The leaves grow for the stalk, and not directly from the roots of the plant.
A common example of such a plant is a rose, or, for that matter, any other flower, such as a gardenia. One who smells fragrant flowers such as these would recite "Boreh Aseh Besamim." Likewise, the Ben Ish Hai writes that the custom is to recite "Boreh Aseh Besamim" before smelling cloves.
An example of a fragrant plant that does not satisfy these requirements is mint. Mint leaves are herbs that grow directly from the ground, without a stalk, and therefore one who smells mint leaves would recite the Beracha of "Boreh Asbeh Besamim."
It should be noted that liquid produced from a plant has the same status of the plant with respect to this Halacha. Thus, one who smells rosewater would recite the Beracha of "Boreh Aseh Besamim," even though rosewater is liquid, since it is produced from roses.
Interestingly, one who mistakenly recited the Beracha of "She’hakol Niheya Bi-dbaro" before smelling a fragrant substance has fulfilled his obligation, and does not recite another Beracha.
If several different spices which require different Berachot were collected together into a single bundle, and this collection produced a distinct fragrance such that one cannot discern any individual spice, one should recite the Beracha of "Boreh Mineh Besamim." This is the ruling of the Ben Ish Hai. Of course, if the spices are divided into different groups, then one should recite separate Berachot of "Aseh Besamim" and "Asbeh Besamim" over the different bundles. However, if the different plants are collected together and one cannot discern the fragrance of any particular spice, then one should recite before smelling the bundle the generic Beracha of "Boreh Mineh Besamim."
Summary: One who smells a fragrant plant with a stalk – such as flowers or cloves – recites the Beracha of "Boreh Aseh Besamim," whereas before smelling herbs that grow directly from the ground – such as mint leaves – one recites "Boreh Asbeh Besamim." If different kinds of spices were bundled together and produced a distinct fragrance, one recites the generic Beracha of "Boreh Mineh Besamim."
