external world. The things referred to in the poem are also particular instances of types and classes of things—the wheelbarrow being a machine, for example, on which life also depends. Furthermore, sensations, feelings, emotions, thoughts, and ideas depend on such things. As the poet expresses it in his poem “A Sort of a Song,” “No ideas/ but in things.” The faculty of the mind that has ideas is the imagination. “The Red Wheelbarrow” is about the relationship between the imagination and reality.

The poem, then, is about how human imagination interprets what the senses relate about reality to the human mind. 

So much depends upon the "so much," if you will.  Whatever associations one finds in the images the poem presents, are dependent upon one's imagination.  It is the imagination that sees and finds meaning in objects, glaze (the sun must now be out following a rain) and water, and chickens.  

Human minds interpret what they experience through their senses and find meaning, and, according to Williams, it is the imagination that interprets and finds meaning.  The other commentators above, for instance, have done just that in interpreting the poem.   

I just read a 3,000-word essay about a 124-word Beatles song. While I was reading, not even half-way through, I thought: This is way too much to say about such a simple, little song. The remaining Beatles, if the were to read the essay, would have a great laugh.

And one must believe that William Carlos Williams must have had quite a laugh out of all the words used to discuss his little poem about an image of a wheelbarrow and some chickens. Indeed, the poem was originally printed, without a title, in a 1923 Williams poetry anthology called Spring and All. Look how simple the poem is without the first four words:

a red wheel

barrow

glazed with rain

water

beside the white

chickens.

It's a picture of contrasts of colors and shapes and textures and things. And what do the first four words say?

so much depends

upon

I don't know... you tell me what depends on that shiny wheelbarrow and those white chickens?

Maybe what the poet is saying is this: stop looking for themes in poetry (and in life). Just look.

The theme would also be life, re-birth, second chances, and the importance of the cycle of life upon everything.

Each verse conveys an image of re-birth, cycles, and entanglement with the universe as a whole.

The life cycle and re-birth are notable in the red wheelbarrow's glaze of "rain water" because it evokes the image of the never ending water cycle that never ends and has been in our planet forever.

It is also represented in the barn and the chickens since another commonly known life cycle is that of the egg/chicken/hen.

The red wheelbarrow itself is the center of it all, and so much depends on it, since it serves in many capacities to help us carry, drag, take, commute..and it is an reflection of ourselves, and how life touches us daily, and we are so indebted to that chance, and to make the best of our time with the efficacy of that red wheelbarrow.

This depends upon (ha ha) your point of view.

To me, this poem is just about how simple, everyday things are important.  It is about how our happiness depends on appreciating dull things like chickens and wheelbarrows that are out in the rain.  In other words, we need to find the joy in our everyday life.  Our happiness depends on that.

Scholars take a much more serious view of the poem.  One explanation, for example, argues that Williams is trying to talk about the relationship between imagination and reality.  That theory believes he is saying that all things are really created by our imaginations.

But poetry is something that everyone can interpret for themselves, so I'm sticking with my idea, which I think is way more understandable.

William Carlos Williams wrote this poem in 1923.  It was supposed to have been written as Williams, a pediatrician, was attending to a very sick young girl.  The poem depicts the image that was outside her window.

Williams would have been influenced by the Imagist poets, like Ezra Pound.  Imagists believed in using their poetry to portray pictures of life all around them.  The deeper, symbolic meanings that are associated with so many Romantic poets were not important - only the clear and pure representation of modern life.  This poem certainly holds true to that form.

However, with this genesis of the poem in mind, readers can connect Williams image to the beauty and importance of life itself.  The red wheelbarrow is symbolic of the blood of life, and the rain of life-giving water.  The white chicken is the innocent person, like an innocent young girl.  So much depends upon her being able to have the necessary elements of life - the blood and the water.  Life should go on.

Considering the time period, there can be another inferred theme.  The Industrial Revolution shifted the focus of this country from agricultural centers to urban centers.  Cities became heavily populated, and factories were tearing up both the landscape and the air quality.  This pure image of farm life is a reminder of how important the agrarian lifestyle is.

What depends upon a red wheelbarrow? 

Answer: So much. 

What is the significance of the glaze of the rain water or the white chickens?

Answer: So much depends upon the reader/observer. 

There is no "I" in the poem. There are no capital letters, rhyme or meter. The objects are ordinary. Aside from the reference to agriculture or labor (farming), this scene is of objects with no overt meaning. This scene, sparsely described, is an example of Imagist poetry, the poetic attempt at painting a picture. Williams was attempting a new kind of poetry, perhaps even beyond Imagism. With no discernible style, no punctuation and no cultural or historical references, this is an image, plain and simple; there are just words which stand for things.  This might sound ridiculously simplistic, but it goes to the heart of the poem. Words depend on things. We depend on words to communicate things (and ideas).

Using this plain image, the reader focuses on the word/images, the odd line breaks and maybe even the choice of prepositions. Why "red?" Why "a" and not "the" wheelbarrow?  Why "chickens"?  Regardless of the poet, I'm of the school that the reader's interpretation is the creation of meaning. But even moreso in cases like Imagistic poetry. 

To answer your question, my (and this is only one interpretation) impression of the poem is about nature and industry, represented by the chickens/rain and wheelbarrow respectively. The wheelbarrow implies human industry but there is no human in the poem. The chickens and rain (plant growth, drinking water, life, etc.) represent nature; chickens a source of food. So a basic interpretation is that so much depends upon nature and industry for survival. But to be honest, I would call this a dumbed down impression. The significance of this poem is that so much depends upon words which depend upon things; for good or bad. As these are simplistic things, another interpretation could be that this is a criticism on the accumulation of unnecessary things.  Instead, Williams offers a focus on more simplistic objects and how they can convey or prompt the reader/observer to form as much meaning and introspection with his/her own imagination --- perhaps even more than a descriptive, stylistic poem might convey.

In this sense, why "chickens," why "a red wheelbarrow," why "glazed with rain" is the whole point - focus on objects themselves. So much depends upon imagination via words via objects.

In Spring and All, Williams writes: “To refine, to clarify, to intensify that eternal moment in which we alone live there is but a single force—the imagination.”