Wheeler’s Dwarf pittosporum turning mottled, yellowed, ending with leaf spot
When healthy, they are deep glossy green. Nutrient deficiency?
Certified GKH Gardening Expert
Maybe nutrient deficiency. But it looks like a possible virus. There is a mosaic virus that goes to pittosporum.
There is no definitive cure for most viral diseases in plants, but they are not necessarily killers. Keep the plant as healthy as possible with good soil and water management.
Applying a complete, mineralized, organic fertilizer that has balanced macro and micronutrients would address the possible nutrient deficiency. It would also support the plant health in case it is a virus. This is the best fertilizer I know of, short of getting soil analysis and an Rx for amendments.