Maryland Celebrate Arbor Day! Arbor Day was started in the state of Nebraska in 1854 by Julius Sterling Morton. Nationally Arbor Day is celebrated on the last Friday in April. Share this:Click to share on X (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Reddit (Opens in new window)Click to email a link to a friend (Opens in new window)Click to print (Opens in new window)