"Grow the beard" is an antonym of "jump the shark." In other words, it's when a show that starts off in Suck Town hits its stride. The term comes from Star Trek: The Next Generation, which started off terrible but began to get better when Commander Riker grew a beard at the beginning of season two.
"Man, the first season or two of The Simpsons blew, but after that the show started to grow the beard."
by Walter Wiese April 13, 2006