From what I have read, the weekly Mother of Perpetual Help Novena (at least in the United States) began with the Redemptorists at St Alphonsus Church in St. Louis, MO. After that many other churches started offering Weekly Tuesday Novenas. The days may vary like having it on Wednesday or Monday. I know in the Philippines, this devotion is very popular and is held on Wednesdays.
I must say, this is a very beautiful devotion and it is a devotion that I am happy to see is still popular in our modern time.