Although I have worked in Spain in the past, mainly in the north I have never been to La Palma in the Canaries. Last night it decided to visit me here in the UK. When I went to get in the car this morning it was covered in a good dusting of yellow powder; presumably sulphur from the volcano carried on the wind, The black plastic garden furniture was also coated.
Guess it's as good a way as any to acidify (a little) a chalky garden