August 15th is the Feast of the Assumption, in the Catholic Church and the Feast of the Dormition in the Orthodox Church. Both churches celebrate the day Mary enters into Heaven on August 15th each year. Dormition means "falling asleep" and refers to Mary dying or as the bible puts it "falling asleep in Christ" and entering into Heaven.
The Assumption refers to the beleif that Mary was "assumed" body and soul into Heaven. This beleif does not presuppose that Mary did not die, however. But a beleif in her bodily assumption dates back centuries. There is no credible tradition in ancient Christianity of Mary's permanent burial place like we have with some of the original Apostles, or of her relics, which would be her bodily remains or objects touched to them.
August 15th is still a holiday in France, Italy, Spain and Greece. Unfortunately, it is not even a Holy Day of Obligation this year in many U.S. Diocese because its vigil falls on a Sunday.
The University of Dayton has some fascinating information on the Assumption and customs associated with the feast. This one from Germany was especially interesting:
In Germany, a custom developed which continues today in many parishes. People gather large bouquets of herbs and wildflowers, especially those associated with healing properties. These are brought to the Assumption Vigil or Holy Day Mass, are blessed, and are taken home to be dried and kept for the various purposes of seasoning, healing, and for fragrant decoration of the home.
How wonderful to use God's earthly bounty and His kindness to His mother to gather healing herbs to use year long. What a wonderful way to praise Him!