According to an article in The Washington Post a long dry spell can cause the Tulip trees to shut down some of their leaves, which makes them turn a bright yellow. I’m not sure that we are seeing the beginnings of yellow leaves, but we have come through a long dry spell.
I read on the web sites that people love their Tulip Trees, EXCEPT when they rain sap. “Do not park your cars under a Tulip tree,” and yet I didn’t see much sap on the ground. Maybe the trees in the Pacific Northwest are better behaved. :)
I recently picked up a book by Daniel Chamovitz, “What A Plant Knows.” In the first chapter he writes, “Plants see if you come near them; they know when you stand over them. They even know if you’re wearing a blue or red shirt.” I wonder if the Tulip tree sees me coming by occasionally to see what’s happening?