First time I've planted supertunia bordeaux in garden soil within in a planter. I initially watered with some miracle grow. After a couple weeks of watering there appears to be developing a "yellow dust" on top of the garden soil. When I water the plants the yellow matter appears to "steam". The plants seem fine, but not sure what the yellow dust like matter is or if I should be concerned. The picture of the yellow matter is what it appears like after watering. It certainly seems odd.
