Stanza 1 Summary

Line 1

      What thoughts I have of you tonight, Walt Whitman, for I walked down the sidestreets
under the trees with a headache self-conscious looking at the full moon. 

• The poem begins with an apostrophe. No, not that kind of apostrophe. Here the speaker is talking directly to Walt Whitman, a super-important 19th-century American poet, known for his all-encompassing love of America and his very long lines of poetry. 
• Walt Whitman died in 1892, so he's definitely not walking alongside our speaker. Whitman is part of the speaker's imagination, which is what makes this an apostrophe.
• Why does our speaker conjure up Whitman? Well, it sounds like he's lonely. He wanders down sidestreets—not main streets—looking at the moon. He sounds like he's a bit of a loner. He's thinking of Whitman almost as an imaginary friend. 
• And what an imaginary friend to have. Ginsberg was a big admirer of Whitman, and he owes a huge debt to the dead poet. On the page, Ginsberg's poems look a lot like Whitman's—both poets are known for their signature free verse long lines. Their poems aren't usually structured in traditional forms (like sonnets or villanelles), nor do they usually have regular rhyme schemes or meters. 
• Perhaps Ginsberg conjures up Whitman in his speaker's imagination to acknowledge his influence on his poetry. Or Whitman could be a poetic ideal for the speaker. Or, the speaker could be trying to stake a claim to Whitman's literary inheritance. Maybe he's saying: I am the poetic son of Whitman! In this moment, all of these interpretations are possible, so we'll keep an open mind.

Line 2 

      In my hungry fatigue, and shopping for images, I went into the neon fruit supermarket,
dreaming of your enumerations!

• We learn here that our speaker is tired and hungry. But interestingly, he's not shopping for food. He's shopping for images. Um, just so you know, buddy, those do not stick to your ribs.
• Maybe the speaker's making a comment on American consumer culture here. He's so bombarded by images in magazines, on billboards, on the TV, that he doesn't think of food directly. He thinks of images of food, like the ones slapped on the front of cans. 
• So our speaker goes into the "neon fruit supermarket." It's bright and shiny. It probably has fluorescent lights. It might even be garish. We bet there's an electronic bell that dings when he walks in the door. 
• The speaker is still addressing Whitman in this line, and the speaker says that he dreams of Whitman's "enumerations." Many of Whitman's poems were long and almost list-like. In a lot of poems, Whitman would lovingly enumerate (or catalogue) all the types of people and things in America. 
• As he enters the supermarket, filled with tons and tons of fruits and vegetables, perhaps the speaker imagines making his own kind of enumerations.

Line 3

What peaches and what penumbras! Whole families shopping at night! Aisles full of
husbands! Wives in the avocados, babies in the tomatoes!—and you, Garcia Lorca, what were
you doing down by the watermelons? 

• Now the speaker is getting excited, especially about all this stuff he's seeing in the supermarket. There are so many peaches! But there are also "penumbras," or shadows. He sees a dark side of the supermarket, too. 
• He also sees families shopping together—there are wives "in the avocados" and babies "in the tomatoes." Are there really little mini-ladies inside the tomatoes? Of course not. But we're betting they're among the tomatoes, testing them for ripeness. 
• The supermarket is filled with luscious-sounding fruits and vegetables. Maybe they're a symbol of life, fecundity, or fertility. Then again, maybe they're just fruits and vegetables.
• The speaker then imagines that he sees Federico Garcia Lorca, the Spanish poet and playwright, hanging out by the watermelons, doing something possibly suspicious. He addresses him directly, as he addressed Whitman before. Again, this is all happening in the speaker's head. Garcia Lorca died in 1936, which means we're dealing with another apostrophe.
• An interesting fact about Ginsberg, Whitman, and Garcia Lorca: these three poets were all gay. Is this the most important thing to know about "Supermarket"? Probably not. But it does explain, perhaps, at least one reason that Ginsberg included Whitman and Garcia Lorca in his poem. Ginsberg may be trying to locate his poetic "fathers" in other gay poets. It's like he's imagining that he's descended from them, at least in terms of poetic creativity.