If you have mulch around your house right outside.........I would change that take it to a land fill and put down black cloth & stones instead..............where ever possible where there is not plant a spray vinegar............but not on plants....or near the roots.....you could have gotten this from a nursery 5 years ago.............Look that up on the web.............for many more suggestions............Sorry to hear about this, seems that a lot of people who use mulch right outside their homes get this because of moisture & sun.