National Arbor Day 2024 Theme. Known as the tree planter’s holiday, arbor day is a day for people to come together in recognition of the wonders of trees. April 26, 2024, 2:02 am.

National arbor day is always celebrated on the last friday in april, but many states observe arbor day on different dates throughout the year based on best tree planting times in their area. Trees are more than signals of the changing season.