In previous postings I have talked about how hokku intimately relates to Nature and the seasons, and I have said that the key to hokku is understanding that it expresses the seasons in its subject matter. Merely setting a hokku in a given season is not enough; the hokku must express that season in one of its many manifestations, whether it is reddening leaves, falling leaves, a garden withering, pumpkins, Halloween, and so on.
It should be obvious, then, that the more one is in touch with Nature, the more one will be able to express the nature of a season through understanding natural changes in the world and life around us, as well as in ourselves. One can hardly find a better example of such keeping in touch with Nature than the Journals of Henry David Thoreau, who meticulously noted seasonal changes in the area of Concord, Massachussetts, in the 19th century. We can hardly write with much versatility about autumn if we do not know what Nature is doing in autumn.
Of course there are many good hokku to be written from obvious autumn subjects, but a wider range comes only from learning the changes of Nature from season to season in the place where we live . Autumn in New England will be somewhat different from autumn in the Cascade foothills of the Northwest, and autumn in the Salinas Valley will be different from both. And of course we can say the same of autumn in the Basel region of Switzerland, autumn in the east German region of Bautzen, autumn in the Netherlands, or autumn in Norway or Finland or the south of France, the West Country of England, or the Rhondda Valley of Wales.
Given the huge range of local variation in life and climate, it has simply become impractical to write hokku based on the old season word system, even overlooking its other faults. That is why the “natural” system is preferable in our time. The natural system is the “Thoreau” system — becoming familiar with Nature in its seasonal changes and manifestations in the plant and animal world around us, not just in the category of “human affairs” or the obvious aspects of autumn.