"Fern Hill" is based on Dylan Thomas's childhood experiences at his aunt's farm of the same name. Rather than describe this subject in a straightforward manner, however, Thomas use extravagant language to evoke his memories. In the process, the poem transforms autobiographical material into a general celebration of a childhood spent outdoors. But by the end, the poem has become a lament for the loss of childhood as people grow up.
This language in this poem is characteristic of Thomas. It's a swirl of imagery, sounds, impressions, and allusions that isn't always meant to be taken literally. A poem like "Fern Hill" wants to sweep its reader of their feet, transporting them through a dreamy realm on a journey guided by emotion and imaginative associations. The first step in getting to know a Dylan Tomas poem is to enjoy it, to bask in the poem's sumptuous intensity and its sense of beauty. That said, it is still totally possible to talk about this poem. In fact, there's a lot to say!
The poem begins with the speaker's memory of a typical day at Fern Hill. The speaker lounges "under the apple boughs." Nearby is the "lilting house." The speaker is "happy as the grass was green." These two phrases, "lilting house" and "happy as the grass was green," both use the kind of associative poetic logic that the speaker will turn to throughout the poem. That is, they blend different senses together to create a vivid impression of the speaker's feelings.
"Lilting" means singing or speaking with a gentle rising-and-falling sound. A house that sings isn't a literal image, and this isn't going to be a literal poem. Rather, these early lines hint at how the poem exists in its own universe of richly metaphorical descriptions, where a house can be so wonderful that it sings.
The simile "happy as the grass was green" suggests that the intensity of the speaker's happiness matches the vividness of the grass. Again, senses blur together, so that an emotion (happiness) and a color (green) can be compared to each other, or even fuse into the same thing. This blurring or fusing suggests that the speaker's inner world of emotions and outer world of natural sights are all mixed up together in the poem's heightened version of reality.
The poem begins, "Now as I was young." This "Now" is interesting because it evokes the present tense, while the rest of the poem is in the past tense ("I was"). Of course, "Now" can be interpreted idiomatically here, like beginning a sentence with Now then, or Well, or So guess what. It's a way of getting someone's attention and introducing a train of thought. The speaker mines the richness of this idiom, using it to draw attention to another kind of blurring, this time between past and present. Throughout the poem, the speaker will bask in wonderful memories of the past—memories that almost seem like the present.
These two lines, along with the rest of the poem, are structured syllabically. Syllabics is a formal constraint that modernist poets like Dylan Thomas often used to structure their poems in place of meter. A poem written using syllabics adheres to a certain number of syllables per line, rather than to a certain number of stresses as in traditional meter. These first two lines have 14 syllables each. This establishes a pattern that the first two lines of each stanza will follow.