The Gentian weaves her fringes—
The Maple's loom is red—
My departing blossoms
- F 21 (1858)
Autumn colors blaze: the purple blue of the fringed gentian--which blooms its farewell to summer in September or even early November, the red and orange hues of the maple trees... It's a natural eye-pleasing parade before the leaves and blooms drop from the oncoming cold.
But the poet's garden, and here we assume Dickinson is speaking of her own garden, is fading. The flowers are fading, plants turning brown. These 'obviate' parade--in other words, make a parade unnecessary.
Apparently Dickinson had William Cullen Bryant's poem "To the Fringed Gentian" marked in a book of poetry. This is the penultimate stanza:
I prefer Dickinson's gentians that weave into the Maple's red loom to Bryant's whose dainty little plants look through their lashes at the blue sky that matches their own cerulean tint.
I also like how within a few short lines Dickinson sketches a very visual picture contrasting the woods outside her gate to her own garden enclosed within.