This is a two stanza poem that is separated into sets of ten lines. While it does not contain a single, perfect and unified pattern of rhyme, it is made up almost entirely of half or slant rhymes. These are most prevalent in the corresponding endings of lines one and two as well as lines eleven and twelve. ‘I am Vertical’ by Sylvia Plath is composed of these half rhyming couplets as well as those that rhyme fully. Such as within lines nine and ten and nineteen and twenty. There is enough of a connection between these varying sets that the poem is unified by the pattern.
There is also a vaguely similar pattern of rhythm running through the text. The lines do not conform to a single pattern of meter but the majority of them are around nine-twelve syllables long. There are those of course which break this rule considerably, such as lines twelve and twenty.
A reader should also take note of the literary techniques used by Plath in the text of the poem. First, a reader will notice that the mood is quite dark. The speaker is airing all of her grief and desiring the benefits of her death. These factors of the poem are emphasized through the nighttime setting, under a sky of watching stars, and made more relatable by the personification of the plants. 
Summary of I am Vertical
The poem begins with the speaker stating that she is “vertical” and would like to be “horizontal” instead. One comes to the conclusion later that this position allows her to communicate with the “sky.” It also more closely resembles the positions of gardens she admires. And finally, it is a position of subjugation. She is opening herself up to be acted upon. She is no longer thinking or worrying about her own life.
As the poem continues the speaker describes how she sees plants as being useful. They take from the earth and give back “gleaming” in the spring. She walks among them, but they do not see her. This fact is painful to the speaker and leads her to the determination that she would be better off “finally” dead. Her body would return to the earth and help the world, as the plants do.
You can read the full poem here.
Analysis of I am Vertical
Stanza One
Lines 1-4
But I would rather be horizontal.
I am not a tree with my root in the soil
Sucking up minerals and motherly love
So that each March I may gleam into leaf,
In the first stanza of this piece the speaker begins by responding to the title, “I am vertical.” She makes this statement and then continues into the first line of the poem with, “But I would rather be horizontal.” Without any further description of the speaker’s situation one can assume that she is completely unhappy with her current situation in life. She’d rather be living in the opposite manner that she is.
The next lines move through a few different types of life she does not embody the qualities of. First she mentions trees and how their roots “Suck…up minerals and motherly love.” She is not this kind of being. There is no “gleam[ing]” end goal in sight at the beginning of “March” when spring comes. She is not full of goodness and life.
Lines 5-10
Nor am I the beauty of a garden bed
(…)
And I want the one’s longevity and the other’s daring.
In the next statements, she says that she is not the
[…] beauty of a garden bed
Attracting my share of Ahs and spectacularly painted,
Here, the speaker crafts what she sees as being the image most opposite to herself, a garden bed. She does not shine with the beauty of the blooming flowers. There is no one fawning over her saying, “Ah…” when they observe her flowers. One can assume she sees herself as being dull and without color or points of interest. In addition to the lack of beauty, she also does not have the naivety that comes with being a flower. The flowers do not know they are “soon” to die.
In the final lines of this section, she tells the reader that any tree, compared with her, is “immortal.” Any plant life is more valuable and memorable than she is. The section is concluded with the speaker saying that she would really like to have the “longevity” of a tree and the “daring” of a flower that reaches high.
Stanza Two
Lines 1-3
Tonight, in the infinitesimal light of the stars,
The trees and the flowers have been strewing their cool odors.
I walk among them, but none of them are noticing.
In the next set of ten lines, the speaker brings the narrative into the present moment. The previous stanza was a general speech on how she feels about herself. Now, she is describing “Tonight.” This moment is filled with the “infinitesimal light of the stars.” There are all the smells the “flowers have been strewing.” It seems that the entire moment is taken up by natural beauty. One can assume the speaker will be confronted with her own inadequacies at this time.
The speaker has entered into this landscape and is walking among the previously described flowers, trees, and stars. Although she longs to be noticed as they are noticed by others, she is ignored. There is some sense of recognition she is looking for that she doesn’t receive. She is seeking out a kinship between herself and the organisms she sees as being the most valuable. This would be confirmed for her if they’d “notice” her, but they don’t.
Lines 4-10
Sometimes I think that when I am sleeping
I must most perfectly resemble them —
(…)
And I shall be useful when I lie down finally:
Then the trees may touch me for once, and the flowers have time for me.
It is clear at this point that the speaker is frustrated by her situation. She casts her mind back to moments where she didn’t feel so tormented by inadequacy. The only time she can think of is when she is “sleeping.” She is most like the flowers, in fact, she
[…] perfectly resemble[s] them—
Thoughts gone dim.
It seems that the speaker believes it is her own capacity to think, reason, and worry, that separates her from the flowers. It is interesting to note this perspective within Plath’s poetry. Plath addressed her own feelings of inadequacy and longing for more throughout her poetry. This iteration is more demeaning than others in that her speaker is seeking out a use for herself as well as beauty and perhaps, some internal goodness. This takes precedence over intelligence or a well-reasoned life.
In the final four lines, the speaker describes when and where she feels she is the most useful. It happens when she is “lying down,” like a bed of flowers. In this position, she is able to have an “open conversation” with the sky. They are on the same level and able to communicate more effectively.
The last two lines state that the speaker will find her use when she lies down for the last time. When she is dead, and her body returns to the earth, the “flowers [will] have time for” her.
