I was walking across the patio at the church this morning. Suddenly, smoke swept across the far side of the patio. Was someone burning brush? No, it wasn’t smoke — it didn’t smell like smoke, and it wasn’t blue — it must be dust. But the only way you’d get a dust cloud like that would be if it were very windy, and there was nothing more than a gentle breeze blowing.

Then I looked up. One of the trees in the patio, a non-native tree, some kind of European conifer, was releasing huge clouds of pollen, so much pollen that it looked like smoke.