Mandevilla Plant Leaves Turning Brown. Watch for small brown spots on the leaves. Plants infected with leaf spot should be quarantined and pruned thoroughly to remove all affected foliage and stems.
Keep in mind however that there is no guarantee this will work. These can quickly spread to kill the whole leaf and then the whole plant. 20052014 If temps fall below 50 F the mandevilla plant will die.
Protect your dipladenia and mandevilla from drafts and regularly spray water on their leaves.
Either just the edges or even the whole leaf. So are their feeding habits. Several days after bringing it in the leaves are turning spotted brown and dropping off starting at the base I sprayed the plant twice with Ivory soap and water before bringing it in and put insecticidal spikes in the soil. Just dark browning making the leaf look and feel weakened.