Many plant and tree varieties tend to stress out a bit during the summer months due to the extreme heat, high humidity, and excessive rain that we experience in Tampa Bay area. It’s a common occurrence with crape myrtles, drake elms, hibiscus and roses, to mention a few.
Don’t concern yourself too much: if your plants were fertilized in spring and healthy prior to this weather, they are most likely just going through a transitional phase and trying to adjust to the extreme elements. As summer rain patterns slow up and extreme heat lessens, they should bounce right back.