How can one define or describe the poetic style of Thomas Hardy?

The term "poetic style" may be aptly applied to prose as well as poetry, "poetic" being a word applicable to style as well as genre. There can be no debate that Hardy's descriptive style as employed in his novels is often poetic, often transcending the boundaries of simple prose and becoming long form poetry in its own right.

This is particularly true for Hardy's descriptive passages focusing on natural landscapes, which often provide a symbolic or metaphorical accompaniment to the emotions, thoughts and actions of his characters. Hardy's novel The Return of the Native contains many such examples of poetic prose. For example, this passage from the opening chapter contains alliterative ("pickaxe, plough or spade") and picturesque phrases and internal rhyme (Distilled by the sun, kneaded by the moon, it is renewed in a year, in a day, or in an hour"), as well as lofty speculative thoughts ("Who can say of a particular sea that it is old?"), all lending a poetic quality to the chapter.

To recline on a stump of thorn in the central valley of Egdon, between afternoon and night, as now, where the eye could reach nothing of the world outside the summits and shoulders of heathland which filled the whole circumference of its glance, and to know that everything around and underneath had been from prehistoric times as unaltered as the stars overhead, gave ballast to the mind adrift on change, and harassed by the irrepressible New. The great inviolate place had an ancient permanence which the sea cannot claim. Who can say of a particular sea that it is old? Distilled by the sun, kneaded by the moon, it is renewed in a year, in a day, or in an hour. The sea changed, the fields changed, the rivers, the villages, and the people changed, yet Egdon remained. Those surfaces were neither so steep as to be destructible by weather, nor so flat as to be the victims of floods and deposits. With the exception of an aged highway, and a still more aged barrow presently to be referred to—themselves almost crystallized to natural products by long continuance—even the trifling irregularities were not caused by pickaxe, plough, or spade, but remained as the very finger-touches of the last geological change.