Corey Haim's mom Judy Haim claims she just moved to Toronto -- thirty minutes from where Corey is buried -- so she could be closer to her son.

Judy tells TMZ, she visits the late actor's grave seven days a week ... for an hour or more a day.

According to Judy, the outpouring of support has been incredible -- every time she visits, the grieving mother finds DVD covers, cards, flowers and plants from fans.

Corey Haim -- who starred in several '80s blockbusters like "The Lost Boys" -- passed away last month. He was 38.