Treating Brown Spots on Mandevilla Leaves

Fungal Leaf Spot on Mandevilla

Annette's new Mandevilla has brown spots on most leaves, but no visible insects.

Expert Solution

The symptoms point to a fungal infection. Spray the plant with a broad‑spectrum fungicide such as Daconil or Funginex to halt spread. Existing spotted leaves will eventually drop; focus on protecting new growth. Ensure good air circulation and avoid overhead watering to reduce humidity on foliage.