19 roses represent eternal love. 19 is the homonym for "forever", and the rose represents love, so 19 roses have the meaning of eternal love.
2, there is the meaning of consistent
19=11+5+2+ 1,11 means one lifetime, 521 means I love you. Sending 19 roses to lovers means that they love each other very much, and their unique little thoughts are to stay with each other for life.
