It appears that a haiku must be divided into two sections - what JR calls “the fragment” and “the phrase" - and should only be as long as one breath, although it takes two to speak correctly. There needs to be a syntactical break separating the verse into two distinct divisions, and it pays to be aware of which two lines you wish to make into the phrase.
Here I have made the first two lines "the phrase", although it can also be the the second two lines. It also appears often to me that the haiku is cyclical where the last line returns the reader back to the beginning:
cauld March blast
I also notice that haiku's do not start lines with capitals as with most other poetry. Very inscrutable!