Brown flowers on an azalea plant indicate a serious health problem that requires the attention of a gardener. Healthy azaleas produce attractive flowers that beautify the garden and attract beneficial insects to it; when the flowers are unhealthy, the whole garden will suffer. Treat the azalea to restore it to health or keep the plant alive.
If the azalea flower itself is the only part of the plant that appears to be suffering and turning brown, the azalea has Ovulinia azaleae, or petal blight. This is a fungal disease that affects flowers within a day of contraction, which is why flowers may be healthy one day and brown the next. Petal blight is a serious fungal problem that requires immediate care if the azalea plant is to be saved.
Apply a fungicide designed to treat azaleas or target petal blight in particular. Fungicides can be obtained at gardening centers, where local experts may be able to offer location-specific advice on treatment. Spray the fungicide onto the azalea according to the directions on the package to avoid damaging the plant further. Avoid overapplying the fungicide, as excess chemicals can harm the soil around the azalea and weaken the garden's overall health. Apply fungicide at regular intervals.
Pinch off the brown blossoms and remove them from the garden to stop them from spreading the fungus to other parts of the plant or other areas of the garden. Remove any fallen leaves, petals or flowers from around the azalea plant, as these can serve as host spots for the fungus. Replace the surrounding soil with fresh soil, as the petal blight fungus survives in the ground as well, and add mulch to the top of the soil.
The method of watering is important for keeping azaleas healthy after they have contracted petal blight; overhead watering allows water to become trapped on the leaves and flowers of the plant, which creates a place for the fungus to begin growing again. Add water to the azalea plant's growing environment near the ground to prevent water from remaining on the leaves and petals. Keep the soil moist at all times to keep the azalea healthy.