Le jardin est tout vert*

Although this is a photo I took at the palace gardens in Würzburg, I read the headline on a café's signboard in Brussels. I found it original because it says "the garden is all green" but when I read it out loud, it sounded like all the lines at all the signs during the summer: "le jardin est ouvert" (the garden is open). So, intentional or misspelling?