Post category: Diseases
Root-rot disease and damping-off sometimes occur if plants are over-watered as seedlings or, later, as plants. The roots die and rot sets in. Avoid over-watering and injury during pricking-out. Use clean trays and compost.
Monarda destroyed by powdery mildew
Virus diseases attack many perennial flowers and bulbs, causing mottling or streaking of the foliage, stunting and reduced flowering. Affected plants should be destroyed. Leaf spot diseases of various types sometimes cause red or brown spots on the leaves of many flowers. These are rarely serious.
Powdery mildew attacks some flowers, especially michaelmas daisies and monarda. Spraying is not worthwhile and if the trouble is persistent, grow something else.