Haiku in English is a development of the Japanese haiku poetic form in the English language. Contemporary haiku are written in many languages, but most poets outside of Japan are concentrated in the English-speaking countries. It is impossible to single out any current style, format, or subject matter as definitive. Some of the more common practices in English include: Use of three lines of up to 17 syllables; Use of a season word (kigo); Use of a cut or kire (sometimes indicated by a punctuation mark) to compare two images implicitly. English haiku do not adhere to the strict syllable count found in Japanese haiku,[1] and the typical length of haiku appearing in the main English-language journals is 10–14 syllables.[2][3] Some haiku poets are concerned with their haiku being expressed in one breath[4][5][6] and the extent to which their haiku focus on "showing" as opposed to "telling".[7][8] This is the genius of haiku using an economy of words to paint a multi-tiered painting, without "telling all".[9] Or as Matsuo Bashō puts it, "The haiku that reveals seventy to eighty percent of its subject is good. Those that reveal fifty to sixty percent, we never tire of."[10]
http://en.wikipedia.org/wiki/Haiku_in_English