Pansies are a commonly grown garden flower, and they come in a variety of showy, attractive colours that add beauty to the garden and draw beneficial insects, including bees. However, when the leaves of your pansy show signs of disease, the flowers may be affected as well.
Botrytis blight, also known as grey mould, is a disease that affects pansies. The pathogens belong to the Botrytis fungal species, and there are many of them that have the potential to cause grey mould to appear on the leaves of a pansy plant. As grey mould progresses and grows, it causes a fuzzy grey covering to appear on the leaves, stems and even flowers of the pansy; eventually, infected portions of the plant become decayed and slimy.
Controlling Botrytis Blight
Gray mould kills pansies if left untreated. Serious infections can spread to other portions of the garden, possibly leading to a complete overhaul. Treating the Botrytis blight, as soon as it's detected, is key to keeping your garden healthy. Fungicides that have the chemical chlorothalonil are effective at controlling Botrytis blight, according to the Clemson Cooperative Extension. Pluck infected flowers and leaves and space plants evenly to limit transmission. Avoid overhead watering.
Powdery mildew is a fungal disease that has the potential to severely damage pansies. Like grey mould, powdery mildew produces a white fuzz that covers the leaves and stems of the pansy plant; it starts as small white spots and gradually spreads to envelop whole leaves and plants. As powdery mildew progresses, it causes leaves to prematurely gnarl and die, further weakening the plant.
Controlling Powdery Mildew
Powdery mildew requires fungicides for effective control. A fungicide that contains azoxystrobin is an effective spray for controlling powdery mildew on pansies. As with pansies suffering from Botrytis blight, removing severely infected leaves and plants is one way to stop the disease from spreading. Pinch off dead leaves and remove any fallen leaves from the garden as these host the spores that cause powdery mildew.