Johnny Appleseed Day is celebrated on either March 11th or September 26th each year. The more commonly recognized date is September 26th, which is Johnny Appleseed's acknowledged birthday (he was born September 26, 1774). March 11th is sometimes observed as well because it aligns with the apple tree planting season in some regions. However, most celebrations and recognitions are held on September 26th to honor his birthdate.