Since Shavuot is also called the “Harvest Festival,” it is customary to adorn the home and synagogue with fruits, flowers and greens. Furthermore, our Sages relate that although Mount Sinai was situated in a desert, when the Torah was given the mountain bloomed and sprouted flowers.
NOTE: All floral arrangements should be done early on Tuesday, before the onset of the holiday, to respect the sanctity of Shavuot.