A noteworthy difference between hokku as it was practiced in old Japan and hokku as it is practiced today in English is the method of dealing with season.
The seasons are essential to hokku, one of its defining characteristics. Every hokku is set in a particular season, whether it is an old Japanese hokku or a new English-language hokku.
The difference in method between old and new is this:
In old Japanese hokku, season was indicated by a “season word” that automatically indicated a particular seasonal setting. Unfortunately, this system, over time, became very artificial and cumbersome, requiring elaborately long lists of words and the seasons they indicate, as well as years of study on the part of writers and educated readers, in order to use and understand those words correctly.
In modern English-language hokku, we keep the all-important connection of a hokku with a particular season, but we no longer use long lists of often artificial-seeming season words. Instead, each hokku is marked with the season in which it is written. Then when it is shared with others or published, that seasonal categorization goes along with it.
What that means, in practical use, is that instead of the whole book of season words and their meanings required for old hokku, the writer and reader of modern hokku now only has to know the standard four seasons: spring, summer, autumn/fall, and winter. It takes away the artificiality and the cumbersomeness and the years of study necessary for writing and reading old hokku, and makes it all very free and practical, yet it is still completely in keeping with the spirit of old hokku that requires it be connected to a season.
Perhaps you have noticed that generally, when I discuss old hokku here, I mention the seasons to which they belong. And perhaps you have noticed that I usually discuss spring hokku in the springtime, summer hokku in summer, autumn hokku in autumn, and winter hokku in winter. That too is a part of the old hokku tradition. So hokku are to be both written and read in their appropriate seasons. The only common exception is when out-of-season hokku are used for educational purposes. The rest of the time we read and write a hokku within its correct season. The aesthetic principle behind that practice is that it keeps us in harmony with what is happening in Nature. It also prevents the awkwardness and inappropriateness an aesthetically-educated hokku enthusiast senses on reading an out-of-season verse, the same kind of awkwardness one feels when one sees Christmas lights up in July, or Halloween decorations in the spring.
Our modern practice also, I may add, is often an aid in translating old hokku without awkwardness. For example, here is a spring hokku by Shōha:
Asa kochi ni tako uru mise wo hiraki keri
Morning east-wind at/ kite sell shop wo /open has
If we try to put that in English, we find a problem. A ko-chi is literally an “east wind.” But kochi — “east wind” — is also a season word indicating spring. So under the “old” system we would have to include all of the following as the setting of the hokku in translation:
A morning spring wind
R. H. Blyth, in his translation of Shōha, includes all of that in this order:
A spring breeze this morning:
That makes the first line of the hokku awkwardly long, even though Blyth accurately conveyed the overall meaning (avoiding the literalness of “east wind,” which Western readers would not recognize as a spring season word).
In modern English-language hokku, however, our categorization of each hokku avoids that problem, because Shōha’s verse would appear under its seasonal heading, like this:
The morning breeze;
A shop selling kites
The seasonal indication, which must be included within the old hokku, is instead present as the seasonal categorization preceding the hokku in the new system.
A sequence of several spring hokku by the same or various authors would have the seasonal categorization at the beginning of the sequence, so that readers would know automatically that all the hokku in the sequence are set in spring.
As for the significance of Shōha’s “Morning breeze” hokku, it indicates a unity between Nature and human activity. It is somewhat the opposite of the “If you build it, they will come” used in the movie Field of Dreams. In this case, it is, “If the spring wind blows, a kite shop will open.” It is like “When the weather warms in spring, flowers will bloom.” The combination of the breeze and the shop opening gives us a feeling of the activity of spring — of the Yang (active) aspect of Nature increasing, as yin (passive) decreases.