Pretty much all we know is that the poem takes place outside. We can also say that it's probably summer or spring as there are flowers involved. There are no street signs or time markers, so this could be taking place anywhere that hummingbirds are found (and that's a lot of places).
The one geographical reference we get is to Tunisia, and the speaker lets us know that, compared to the poem's location, Tunis might as well be on another planet. The focus in the poem is on what the speaker sees in an instant, so larger references to the location of the poem actually aren't important here. What matters most are the immediate surroundings—the bush, the bird, and those wonderful wings.