I planted my hawthorn tree 3 years ago and it has never bloomed or grew berries, and it get a leaf disease. Could this be a reason?
Washington Hawthorn Does Not Bloom or Grow Berries
Certified GKH Gardening Expert
Check to see if you have a grafted stock tree. A grafted Hawthorn should bloom in 4 to 5 years.
If it is a seed grown tree you will need more patience, it can be 20 years before it blooms.
Here are a few links for you with some good care information.