Answer: Pink Trumpet Tree (Tabebuia impetiginosa) generally does not develop black leaves so I suspect there's a fungal infection of some sort. It's impossible to diagnose without actually looking at the leaves under a microscope, so I'd suggest you take a sample of the affected leaves (seal them in a plastic bag) to your local nursery or Cooperative Extension office for positive identification. Once the problem has been diagnosed, the nursery or Extension Office can recommend treatment. The phone number for the Orange County Cooperative Extension office is 714-708-2754. Best wishes with your Pink Trumpet Tree.
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