IS IT GOOD WHEN PLANTING FIRE BUSH IN ZONE 10A (SE COAST OF FLORIDA) TO ADD EPSOM SALT TO HOLE BEFORE PANTING
Certified GKH Gardening Expert
You can, but I would recommend dolomitic lime, and wettable sulfur. This will have the same key elements, but will also help stabilize the soil, and give it calcium to go with the magnesium and sulfur. Magnesium and calcium effect each other, and it is necessary to have both to be able to take them up easier.
Here is an article for more information on the plant: https://www.gardeningknowhow.com/ornamental/shrubs/firebush/growing-hamelia-firebush-plants.htm