[From Rosa: The Journal of the Societe des roses du Quebec Rose Society, June 1999, p.7:] The definition of a blind shoot is "a mature stem that fails to produce a flower".
One of the causes of this is a cool spring but they may appear anytime during the growing season and sometimes may be difficult to detect. Instead of a bud at the end of a growing shoot, it terminates with small leaves similar to a husk of wheat. When you are sure the shoot is blind, cut it back by half its length to a strong outward-facing bud. By doing so, the new growth should grow and flower normally.