"In Quamquam Pluries, an encyclical by Pope Leo XIII promulgated on August 15, 1889, the Supreme Pontiff ordered that a special prayer to St. Joseph be added in perpetuity to the Most Holy Rosary throughout the month of October every year. In these times, however, with the Church and fatherhood and the family under such savage demonic attack, it might be a very good idea to add this prayer to the Rosary all year long.
Please read the encyclical — it is very short and very clear and straightforward, and very powerful. The link to it on the Vatican website is right at the beginning of the above paragraph.
Here is the prayer to St. Joseph that Pope Leo XIII attached to that encyclical. (By the way, don't forget that this holy pope also gave us the prayer to St. Michael the Archangel that we say after Low Mass.)"--- David Kaftal
Prayer to Saint Joseph
To thee, O blessed Joseph, we have recourse in our affliction, and having implored the help of thy thrice holy Spouse, we now, with hearts filled with confidence, earnestly beg thee also to take us under thy protection. By that charity wherewith thou wert united to the Immaculate Virgin Mother of God, and by that fatherly love with which thou didst cherish the Child Jesus, we beseech thee and we humbly pray that thou wilt look down with gracious eye upon that inheritance which Jesus Christ purchased by His blood, and wilt succor us in our need by thy power and strength.
Defend, O most watchful guardian of the Holy Family, the chosen off-spring of Jesus Christ. Keep from us, O most loving Father, all blight of error and corruption. Aid us from on high, most valiant defender, in this conflict with the powers of darkness. And even as of old thou didst rescue the Child Jesus from the peril of His life, so now defend God's Holy Church from the snares of the enemy and from all adversity. Shield us ever under thy patronage, that, following thine example and strengthened by thy help, we may live a holy life, die a happy death, and attain to everlasting bliss in Heaven. Amen.