Gail from Palm Coast, Florida writes
My plants are very diseased and the Neem Oil I use at maximum strength has not cured the disease. On the Hibiscus the leaves turn yellow and/or brown and fall off, on the Allamanda and Copper plants the leaves turn brown and fall off. The brown on all the plants looks crisp--like they are burned, but they get regular water and I only use slow release fertilizer.
Fung-onil Multi Purpose Fungicide Concentrate is labeled for use on flowering plants and shrubs in general, however the product label does not list hibiscus or allamanda plants, specifically. We recommend that you first identify the nature of what is causing the injury to your plants before applying more products to them. We suggest contacting a local Master Gardener or using a plant hotline through a local botanical garden for better assistance with diagnosing what is damaging your plants.
Answer last updated on: 02/10/2020
