My potted dahlias have white stuff on leaves

Question

My Dahlias are in very large pots, and at first were beautiful, now after a wet summer the leaves are covered in a white dusty stuff and buds are dying before opening. Help !

Answer 1

This article describes some typical problems that potted dahlias experience: https://www.gardeningknowhow.com/ornamental/bulbs/dahlia/dahlia-pests-and-diseases.htm

From your description, it sounds as though your dahlias have a case of powdery mildew. This article has info on how to deal with that:
https://www.gardeningknowhow.com/ornamental/bulbs/dahlia/dahlias-with-powdery-mildew.htm