I have a perimeter of Pittosporum tenuifolium hedges around my house. About a year or so ago, one section starting dying off, turning brown etc. I wrote it off as perhaps the drip watering was probably disturbed (dogs) as it could not be easily accessed due to a trampoline being in front of them. Then the area spread another 10-15 feet, slowly the plant after plant turned brown and died. When I was digging them up this weekend, I noticed some tiny white worms in the root dirt.

I don't want to replant again if there is something wrong with the dirt that I should take care of first. I can't believe that they didn't get some water as these plants were over seven years old, 15-20 feet high and the drip system watered like 45 minutes (2 GPH) every other day. Located in SF CA Bay Area.

Thanks!