I have five hibiscus plants in the front of my house. Four of them are fine. However, the leaves began turning yellow and falling off on only one of them. I gave it extra fertilizer and water, but now the branches are basically bare. I checked it for bugs and do not see any. I do not understand why this one is having problems when conditions for all five are the same. It looks as though new leaves are sprouting on the branches, but I am not sure they will continue to grow. It was still producing flowers for a time, but then the buds dry up. I don't know what to do to help it and it looks absolutely terrible.
1 of 5 Hibiscus Plants Losing All Its Leaves
Certified GKH Gardening Expert
I would be willing to bet that even though you did not see pests, the plants still has a pest infestation. If it was a disease, it would likely not regrow leaves. Some pests,like thrips or mites, can be difficult to see with the naked eye. I would treat the plant with neem oil. This will kill any harmful pests on the plant without being a danger to people or pets in the yard. Here is more information on neem oil: