I took cuttings of my sage and rosemary and arranged them in a vase on my kitchen window sill...I had mysterious black dusty flecks also. I assumed the cuttings were dying and falling apart. But after looking closely I noticed a worm eating my plants! The flecks were what I assume were it's waste. Not sure if it's the same thing but the description of the flecks sound exactly the same...
I took cuttings of my sage and rosemary and arranged them in a vase on my kitchen window sill...I had mysterious black dusty flecks also. I assumed the cuttings were dying and falling apart. But after looking closely I noticed a worm eating my plants! The flecks were what I assume were it's waste. Not sure if it's the same thing but the description of the flecks sound exactly the same...