It is a mitzvah to gather together and wave four species on the holiday of Sukkot: etrog, palm, myrtle and willow. The palm is known as a lulav, though the term is sometimes used to refer to the four collectively, since the lulav is the largest among them.
The proper time for waving is in the morning — either before the morning service or during the service immediately before the Hallel. Prior to waving, the following blessing is recited.
Blessing for Waving the Lulav
“Blessed are You, Lord our God, King of the Universe, who has sanctified us with His commandments and has commanded us concerning the waving of the lulav.”
Barukh atah Adonai Eloheinu melekh ha’olam asher kid’shanu b’mitzvotav v’tzivanu al netilat lulav.
On the first day of waving add:
“Blessed are You, Lord our God, King of the Universe, who has granted us life, sustenance, and permitted us to reach this season.”
Barukh atah Adonai Eloheinu melekh ha’olam shehehiyanu v’kiyemanu v’higiyanu lazman hazeh.