I suppose we just have to disagree.
But your recollection differs from the text of speech, which can be read at http://www.washingtonpost.com/wp-dyn/content/article/2006/01/31/AR2006013101468.html.
And it differs from what I hear just before the 51:00 mark at the CSPAN video of the speech, which can be viewed at http://www.c-spanvideo.org/program/190900-2. It sounds like Bush says “switch grass” to me.