on black porous stone
The "rules" according to Jane Reichhold (Writing and Enjoying Haiku: A Hands-on Guide):
1. three lines, short-long-short, ignoring syllable count*
2. should contain a fragment and a phrase
3. contain some element of nature
4. verbs in present tense
5. don't use capitals or punctuation
6. avoid rhymes
* According to Reichhold, Japanese counts syllables differently than English does. The usual way of English haiku of 5-, 7- and 5-syllable lines doesn't translate properly within the spirit of haiku. Also, Japanese naturally has 5- and 7-on (how they count "syllables") phrases, as well as seasonal words (which English lacks).
After reading the first half of this book, I'm pretty convinced that haiku is either A) an art peculiar to the Japanese language, untranslatable to English, or B) heck with that! I'll do whatever I want! - and the latter seems to be more where Reichhold is heading, within the guidelines, of course. There are nuances in Japanese that is completely absent from English: seasonal words, punctuation words, phrases that just happen to have the right number of whatsits... So is it even appropriate to try to write haiku in a language that is so flat? Here's the same question in a different context: Is it appropriate to belly dance to music that is not Middle Eastern? Ask 10 people, get 12 answers.
Art is fluid, passing from culture to culture, picking up a little here, a little there, and leaving some behind. The Romany people are experts at this! Leaving pieces of their culture as they migrated (fled) India into the West, adopting things from their host countries in their attempts to survive. I'm not Japanese (not in this or any life, as far as I know), and I don't speak their language, but I don't think that should preclude me from using an art form that is "theirs." I do believe there are conventions that should be followed within any art form. Belly dancing to "Brick House" is just wrong, IMNSHO, and writing haiku about a football game would be, too - though I can imagine exceptions to both.
Are there Rights and Wrongs in art? Yes, I think there are, but I also know that nothing stays the same, and things that don't grow/evolve will stagnate and die. Vive l'évolution!
Photo is mine, taken at the Olivine Pools, Maui, HI; June 2007.